C语言版数字转英文(浮点)
c语言字符串转换成浮点数
c语言字符串转换成浮点数
C语言中的字符串可以被转换成浮点数。
这一过程可以通过使用C语言的库函数完成，其中最常用的函数是atof()。
该函数接受一个字符串作为参数，并返回该字符串所代表的浮点数。
例如，以下代码将字符串'3.14'转换为浮点数并将其打印出来： ```
#include <stdio.h>
#include <stdlib.h>
int main() {
char str[] = '3.14';
float num = atof(str);
printf('The float number is: %f', num);
return 0;
}
```
输出结果为：
```
The float number is: 3.140000
```
需要注意的是，atof()函数仅能将合法的浮点数字符串转换成浮点数。
如果字符串不是合法的浮点数格式，该函数将返回0.0。
因此，在使用该函数时应当保证字符串的格式正确。
c语言字符串和浮点数相互转换
c语言字符串和浮点数相互转换摘要：一、引言二、C 语言中字符串与浮点数的转换方法1.字符串转换为浮点数2.浮点数转换为字符串三、总结正文：一、引言C 语言是一种广泛应用于计算机领域的编程语言，它具有丰富的功能和灵活性。
在C 语言中，字符串和浮点数是两种常见的数据类型。
字符串常用于存储文本信息，而浮点数则用于表示实数。
在实际编程过程中，我们常常需要将字符串和浮点数相互转换。
本文将介绍C 语言中字符串与浮点数相互转换的方法。
二、C 语言中字符串与浮点数的转换方法1.字符串转换为浮点数要将字符串转换为浮点数，可以使用C 语言中的`atof()`函数。
`atof()`函数的作用是将字符串转换为浮点数，它接受一个字符串作为参数，并返回一个浮点数。
例如：```c#include <stdio.h>#include <stdlib.h>int main() {char str[] = "3.14";float num = atof(str);printf("转换后的浮点数为：%f", num);return 0;}```2.浮点数转换为字符串将浮点数转换为字符串，可以使用C 语言中的`printf()`函数或者`sprintf()`函数。
`printf()`函数适用于简单的格式输出，而`sprintf()`函数则可以指定输出格式。
例如：```c#include <stdio.h>int main() {float num = 3.14;printf("转换后的字符串为：%f", num); // 使用printf() 函数char str[100];sprintf(str, "转换后的字符串为：%.2f", num); // 使用sprintf() 函数，保留两位小数printf("转换后的字符串为：%s", str);return 0;}```三、总结本文介绍了C 语言中字符串与浮点数相互转换的方法。
c语言中数字转换成英文对应的字母
C语言中数字转换成英文对应的字母随着计算机编程语言的不断发展和完善，C语言作为一种高效而又易学的编程语言，被广泛应用于系统编程和应用软件开发领域。
在C语言中，对数字进行转换成英文对应的字母的需求也是比较常见的，比如用于开发游戏、数据处理和计算机图形学等应用场景。
本文将介绍在C语言中实现数字转换成英文对应的字母的方法和技巧。
1. 使用数组在C语言中，我们可以通过定义一个数组来存储0到9的英文单词，然后根据数字来索引数组中的对应英文单词。
比如我们可以定义一个字符数组char *nums[] = {"zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"};，然后根据需要将数字转换成对应的英文单词。
这种方法简单高效，适用于小范围的数字转换。
2. 使用switch语句除了数组之外，我们还可以使用switch语句来实现数字转换成英文对应的字母。
首先我们需要定义一个函数，函数的参数是一个整型数字，然后在函数内部使用switch语句根据不同的数字返回对应的英文单词。
这种方法更加灵活，适用于多种情况下的数字转换。
3. 使用递归在C语言中，我们还可以使用递归的方法来实现数字转换成英文对应的字母。
我们可以定义一个函数，函数的参数是一个整型数字，然后在函数内部判断数字的位数，分别处理个位、十位和百位的数字，最终将它们组合起来得到最终的英文单词。
这种方法比较复杂，但适用于大范围的数字转换。
4. 实例分析我们来看一个具体的例子，比如将数字1234转换成英文对应的字母。
我们可以使用递归的方法，先处理个位数字4，得到"four"，然后处理十位数字3，得到"thirty"，最后处理百位数字1，得到"one"。
c语言字符串转浮点数变为999
c语言字符串转浮点数变为999English Answer:Introduction: Converting strings to floating-point numbers is a common task in programming. In C language, the `strtod()` function is used for this purpose. However, sometimes the conversion may not be accurate, and theresult may be different from the expected value.The Problem: In the case described, the string "999" is being converted to a floating-point number. However, the result is not 999 but a much larger number, such as1.7976931348623157e+308. This is because the `strtod()` function is unable to interpret the string correctly.The Reason: The `strtod()` function expects a string that represents a valid floating-point number. A valid floating-point number must have a decimal point or an exponent. The string "999" does not meet these criteria, so the `strtod()` function is unable to parse it correctly.The Solution: There are two ways to solve this problem. One is to use a different function that is specifically designed to convert strings to integers. The other is to modify the string to make it a valid floating-point number.The first solution is to use the `atoi()` function. The `atoi()` function converts a string to an integer. In this case, we can use the `atoi()` function to convert thestring "999" to an integer, and then convert the integer to a floating-point number.The second solution is to modify the string "999" to make it a valid floating-point number. We can do this by adding a decimal point to the string. For example, we can change the string "999" to "999.0". The `strtod()` function will be able to parse this string correctly and convert it to the floating-point number 999.Here is an example code that demonstrates the two solutions:c.#include <stdio.h>。
C语言中将数字转换为字符串的方法
C语言中将数字转换为字符串的方法C语言提供了几个标准库函数，可以将任意类型(整型、长整型、浮点型等)的数字转换为字符串。
以下是用itoa()函数将整数转换为字符串的一个例子：# include <stdio. h># include <stdlib. h>void main (void);void main (void){int num = 100;char str[25];itoa(num, str, 10);printf("The number 'num' is %d and the string 'str' is %s. \n" , num, str);}itoa()函数有3个参数：第一个参数是要转换的数字，第二个参数是要写入转换结果的目标字符串，第三个参数是转移数字时所用的基数。
在上例中，转换基数为10。
下列函数可以将整数转换为字符串：----------------------------------------------------------函数名作用----------------------------------------------------------itoa() 将整型值转换为字符串itoa() 将长整型值转换为字符串ultoa() 将无符号长整型值转换为字符串----------------------------------------------------------请注意，上述函数与ANSI标准是不兼容的。
能将整数转换为字符串而且与ANSI标准兼容的方法是使用sprintf()函数，请看下例：#include<stdio.h># include <stdlib. h>void main (void);void main (void){int num = 100;char str[25];sprintf(str, " %d" , num);printf ("The number 'num' is %d and the string 'str' is %s. \n" , num, str);}在将浮点型数字转换为字符串时，需要使用另外一组函数。
C有关数据类型转换大全
C++有关数据类型转换大全来源：中国自学编程网发布日期：2007-05-21int i = 100;long l = 2001;float f=300.2;double d=12345.119;char username[]=\"程佩君\";char temp[200];char *buf;CStri ng str;_varia nt_t v1;_bstr_t v2;一、其它数据类型转换为字符串短整型(int)itoa(i,temp,10);/〃将i转换为字符串放入temp中，最后一个数字表示十进制itoa(i,temp,2); ///按二进制方式转换长整型(long)ltoa(l,temp,10);浮点数(float,double)用fcvt可以完成转换，这是MSDN中的例子：int decimal, sig n;char *buffer;double source = 3.1415926535;buffer = _fcvt( source, 7, &decimal, &sig n );运行结果:source: 3.1415926535 buffer: ' 31415927' decimal: 1 sign: 0 decimal表示小数点的位置,sign表示符号:0为正数，1为负数CString 变量str = \"2008 北京奥运\";buf = (LPSTR)(LPCTSTR)str;BSTR变量BSTR bstrValue = ::SysAllocString(L\"程序员\");char * buf = _com_util::Co nvertBSTRToStri ng(bstrValue);SysFreeStri ng(bstrValue);AfxMessageBox(buf);delete(buf);CComBSTR 变量CComBSTR bstrVar(\"test\");char *buf = _com_util::Co nvertBSTRToStri ng(bstrVar.m_str);AfxMessageBox(buf);delete(buf);_bstr_t 变量_bstr_t类型是对BSTR的封装，因为已经重载了=操作符，所以很容易使用_bstr_t bstrVar（\"test\"）;con st char *buf = bstrVar;/// 不要修改buf 中的内容AfxMessageBox(buf);通用方法（针对非COM数据类型）用sprintf完成转换char buffer[200]; char c = ' 1'int; i = 35; long j = 1000; float f = 1.7320534f; sprintf( buffer, \"%c\",c); spri ntf( buffer, \"%d\",i); spri ntf( buffer, \"%d\",j); spri ntf( buffer, \"%f\",f);二、字符串转换为其它数据类型strcpy(temp,\"123\");短整型(int)i = atoi(temp);长整型(long)l = atol(temp);浮点(double)d = atof(temp);CString 变量CStri ng n ame = temp;BSTR变量BSTR bstrValue = ::SysAllocString(L\"程序员\");...///完成对bstrValue的使用SysFreeStri ng(bstrValue);CComBSTR 变量CComBSTR类型变量可以直接赋值CComBSTR bstrVar1(\"test\");CComBSTR bstrVar2(temp);_bstr_t 变量[Page]_bstr_t类型的变量可以直接赋值_bstr_t bstrVar1(\"test\");_bstr_t bstrVar2(temp);三、其它数据类型转换到CStri ng使用CString的成员函数Format来转换，例如: 整数（int） str.Format(\"%d\",i);浮点数(float)str.Format(\"%f\",i);字符串指针(char *)等已经被CString构造函数支持的数据类型可以直接赋值str = user name;对于Format所不支持的数据类型，可以通过上面所说的关于其它数据类型转化到char *的方法先转到char *，然后赋值给CString变量。
C语言各种数值类型转换函数
C语言各种数值类型转换函数atof(将字符串转换成浮点型数)atoi(将字符串转换成整型数)atol(将字符串转换成长整型数)strtod(将字符串转换成浮点数)strtol(将字符串转换成长整型数)strtoul(将字符串转换成无符号长整型数)toascii(将整型数转换成合法的ASCII 码字符)toupper(将小写字母转换成大写字母)tolower(将大写字母转换成小写字母)atof(将字符串转换成浮点型数)相关函数 atoi,atol,strtod,strtol,strtoul表头文件 #include <stdlib.h>定义函数 double atof(const char *nptr);函数说明 atof()会扫描参数nptr字符串,跳过前面的空格字符,直到遇上数字或正负符号才开始做转换,而再遇到非数字或字符串结束时('\0')才结束转换,并将结果返回。
参数nptr字符串可包含正负号、小数点或E(e)来表示指数部分,如123.456或123e-2。
返回值返回转换后的浮点型数。
附加说明 atof()与使用strtod(nptr,(char**)NULL)结果相同。
范例 /* 将字符串a 与字符串b转换成数字后相加*/#include<stdlib.h>main(){char *a=”-100.23”;char *b=”200e-2”;float c;c=atof(a)+atof(b);printf(“c=%.2f\n”,c);}执行 c=-98.23atoi(将字符串转换成整型数)相关函数 atof,atol,atrtod,strtol,strtoul表头文件 #include<stdlib.h>定义函数 int atoi(const char *nptr);函数说明 atoi()会扫描参数nptr字符串,跳过前面的空格字符,直到遇上数字或正负符号才开始做转换,而再遇到非数字或字符串结束时('\0')才结束转换,并将结果返回。
C语言itoa（）函数和atoi（）函数详解（整数转字符C实现）
C语⾔itoa（）函数和atoi（）函数详解（整数转字符C实现）C语⾔itoa()函数和atoi()函数详解(整数转字符C实现)C语⾔提供了⼏个标准库函数，可以将任意类型(整型、长整型、浮点型等)的数字转换为字符串。
1.int/float to string/array:C语⾔提供了⼏个标准库函数，可以将任意类型(整型、长整型、浮点型等)的数字转换为字符串，下⾯列举了各函数的⽅法及其说明。
● itoa()：将整型值转换为字符串。
● ltoa()：将长整型值转换为字符串。
● ultoa()：将⽆符号长整型值转换为字符串。
● gcvt()：将浮点型数转换为字符串，取四舍五⼊。
● ecvt()：将双精度浮点型值转换为字符串，转换结果中不包含⼗进制⼩数点。
● fcvt()：指定位数为转换精度，其余同ecvt()。
除此外，还可以使⽤sprintf系列函数把数字转换成字符串，其⽐itoa()系列函数运⾏速度慢2. string/array to int/floatC/C++语⾔提供了⼏个标准库函数，可以将字符串转换为任意类型(整型、长整型、浮点型等)。
● atof()：将字符串转换为双精度浮点型值。
● atoi()：将字符串转换为整型值。
● atol()：将字符串转换为长整型值。
● strtod()：将字符串转换为双精度浮点型值，并报告不能被转换的所有剩余数字。
● strtol()：将字符串转换为长整值，并报告不能被转换的所有剩余数字。
● strtoul()：将字符串转换为⽆符号长整型值，并报告不能被转换的所有剩余数字。
以下是⽤itoa()函数将整数转换为字符串的⼀个例⼦：# include <stdio.h># include <stdlib.h>void main (void){int num = 100;char str[25];itoa(num, str, 10);printf("The number 'num' is %d and the string 'str' is %s. \n" ,num, str);}itoa()函数有3个参数：第⼀个参数是要转换的数字，第⼆个参数是要写⼊转换结果的⽬标字符串，第三个参数是转移数字时所⽤的基数。
c语言字符串和浮点数相互转换
c语言字符串和浮点数相互转换摘要：1.C语言中字符串与浮点数的转换方法2.字符串与浮点数转换的实现原理3.常用函数及其使用示例4.注意事项与技巧正文：C语言中，字符串与浮点数的转换在实际编程中非常常见。
掌握这种转换方法，可以方便地在控制台输出或读取字符串和浮点数。
下面将详细介绍C语言中字符串与浮点数的转换方法及其注意事项。
一、字符串与浮点数的转换方法在C语言中，字符串与浮点数的转换主要通过以下几个常用函数实现：1.将浮点数转换为字符串：- sprintf：将格式化的浮点数输出到字符串中。
- strftime：将指定的格式化的浮点数转换为字符串。
2.将字符串转换为浮点数：- atof：将字符串转换为浮点数。
- strtof：将字符串转换为浮点数。
二、字符串与浮点数转换的实现原理C语言中的字符串与浮点数转换，实际上是对字符串和浮点数的数据类型进行相互转换。
在转换过程中，需要注意以下几点：1.浮点数转换为字符串时，需要指定格式化字符串，如小数点的位置、是否输出负号等。
2.字符串转换为浮点数时，需要确保字符串中只包含数字和可选的小数点，排除其他字符。
三、常用函数及其使用示例1.将浮点数转换为字符串：- 使用sprintf函数，格式化输出浮点数。
示例：```#include <stdio.h>double num = 3.1415926;char str[100];sprintf(str, "%.2f", num); // 输出"3.14"```2.将字符串转换为浮点数：- 使用atof函数，将字符串转换为浮点数。
示例：```#include <stdio.h>char str[] = "3.14";double num;num = atof(str); // 存储结果printf("num = %lf", num); // 输出"num = 3.140000"```四、注意事项与技巧1.在进行字符串与浮点数转换时，注意数据精度的丢失。
keil c语言十六进制数组转浮点
keil c语言十六进制数组转浮点标题：Keil C语言：十六进制数组转浮点数（Hexadecimal Array to Floating-Point）引言：在嵌入式系统和开发领域，Keil C语言是一种广泛使用的编程语言。
它为开发人员提供了一种灵活而强大的方式来编写嵌入式应用程序。
本文将探讨Keil C语言中十六进制数组转浮点数的方法，将帮助您解决实际应用中遇到的问题。
第一部分：介绍1. Keil C语言的特点Keil C语言是一种嵌入式C编程语言，用于开发嵌入式系统和应用程序。
它具有许多优点，如高效性、可移植性以及灵活性。
Keil C编译器是一种高度优化的编译器，适合于不同类型的嵌入式处理器。
2. 十六进制数组和浮点数在计算机中，十六进制是一种表示数值的方法，使用0-9和A-F表示16个不同的数字。
浮点数是一种用于表示实数的方法，包括小数和指数部分。
十六进制数组可以用于存储和传输数据，而浮点数则广泛应用于科学计算、图形处理和嵌入式系统等领域。
第二部分：十六进制数组转浮点数的概要1. 步骤概览将十六进制数组转换为浮点数的基本思路是将数组的字节重新排列，并根据IEEE标准解释其中的位模式。
步骤如下：- 检查数组的字节顺序（大端序或小端序）。
- 将字节按正确的顺序拼接成单个整数。
- 创建一个浮点数指针，将整数存储到该指针指向的内存位置。
- 通过解释内存中的位模式，获得相应的浮点数。
第三部分：详细解释步骤1. 检查字节顺序在Keil C语言中，可以使用预处理指令`#pragma`来检查系统的字节顺序。
例如，使用`#pragma pack(push, 1)`指令将数据结构按照字节对齐原则进行压缩，然后使用`#pragma pack(pop)`指令恢复默认设置。
2. 拼接字节根据字节顺序将数组中的字节拼接为一个整数。
对于大端序（Big-Endian）系统，最高位字节先于低位字节；而对于小端序（Little-Endian）系统，最低位字节先于高位字节。
c浮点数转字符串
c浮点数转字符串C语言中，浮点数转字符串是一个常见的操作。
在实际开发中，我们可能需要将浮点数转换为字符串，以便进行输出或存储等操作。
本文将介绍C语言中浮点数转字符串的方法。
一、sprintf函数sprintf函数是C语言标准库中的一个函数，它可以将格式化的数据输出到一个字符串中。
具体用法如下：```int sprintf(char *str, const char *format, ...);```其中，str表示输出的字符串缓冲区，format表示格式化字符串，...表示可变参数列表。
例如，要将浮点数f转换为字符串s，并保留两位小数，可以使用以下代码：```float f = 3.1415926;char s[20];sprintf(s, "%.2f", f);printf("%s\n", s);```输出结果为：3.14二、gcvt函数gcvt函数是C语言标准库中的一个函数，它可以将浮点数转换为字符串，并指定小数位数。
具体用法如下：```char *gcvt(double value, int ndigit, char *buf);```其中，value表示要转换的浮点数，ndigit表示要保留的小数位数，buf表示输出结果缓冲区。
例如，要将浮点数f转换为字符串s，并保留两位小数，可以使用以下代码：```float f = 3.1415926;char s[20];gcvt(f, 2, s);printf("%s\n", s);```输出结果为：3.14三、dtostrf函数dtostrf函数是Arduino中的一个函数，它可以将浮点数转换为字符串，并指定小数位数和总位数。
具体用法如下：```char *dtostrf(double val, signed char width, unsigned char prec, char *s);```其中，val表示要转换的浮点数，width表示输出结果的总位数，prec 表示要保留的小数位数，s表示输出结果缓冲区。
c语言 最快的数字转字符串的算法
c语言最快的数字转字符串的算法摘要：一、引言二、C 语言中数字转字符串的需求三、分析各种算法及其优缺点1.经典算法2.改进的算法3.其他算法四、结论正文：一、引言数字转字符串是编程中常见的需求，尤其在C 语言中。
在许多场景中，我们需要将整数或浮点数转换为字符串表示，以便于输出或进一步处理。
然而，对于大规模的数据处理，如何快速高效地实现数字转字符串是一个值得探讨的问题。
二、C 语言中数字转字符串的需求在C 语言中，我们可以使用`sprintf`、`printf`等函数将数字转换为字符串。
但是，这些函数的性能可能无法满足大规模数据处理的需求。
因此，寻找更高效、更快速的数字转字符串算法成为了许多程序员的追求。
三、分析各种算法及其优缺点1.经典算法经典算法通常采用循环，将数字的每一位转换为字符，并添加到字符串中。
这种方法的优点是简单易懂，但缺点是效率较低，尤其是对于大规模数据处理。
2.改进的算法为了提高效率，有许多针对经典算法的改进。
例如，可以采用跳跃式转换，减少循环的次数；或者使用字符串缓冲区，一次性将数字转换为字符串，避免多次字符串操作。
这些改进方法在一定程度上提高了转换速度，但仍有一定的优化空间。
3.其他算法除了上述改进方法，还有一些其他的高效算法。
例如，可以利用数字的位运算特性，实现快速转换；或者利用C 语言的指针操作，实现更高效的数字转字符串。
这些算法在特定场景下具有更高的性能，但需要较高的编程技巧。
四、结论总之，C 语言中数字转字符串的算法有多种实现方式，不同场景下有不同的高效算法。
程序员可以根据实际需求，选择合适的算法进行实现。
C语言编写的英语数字转化代码(数字转化为用英语表达的数字)
#include"stdio.h"main (){FILE *fp ;int i ,n ,g,s;char *a[20]={"zero","one","two","three","four","five","six","seven","eight", "nine ","ten","eleven","twelve","thirteen","fourteen","fifteen","sixteen","seventeen","eighteen","nineteen"},*b[10]= {"","","twenty","thirty","fourty","fifty","sixty","seventy","eighty","ninety "};fp=fopen("f:\\ENGLISH2.txt","w") ;for (n=0;n<1000;n++){i=rand()%99;if(i<20)fprintf(fp,"%6s\n",a[i]);else if(i<100){s=i/10;g=i%10;if(g==0)fprintf(fp,"%s\n",b[s]);else fprintf(fp,"%s-%s\n",b[s],a[g]);}};fclose(fp);getch();}把代码复制（ctrl+c）然后在编程软件中运行就可以出来结果！sixtentwotensixteenseventeenfifteenfifteeneightsixfoureighteenelevennineteentwelvezerotwelveonethreesevennineteen onetenfive fourteen nine twelve eleven nineteen sixteen one eleven fifteen thirteen fourteen ten nineteen fifteen one twelve nine eight sixfour twelve three sixfour nineteen eleven seven zero fifteen twelve eight six seven two fourteen nine nine three sixoneten eighteen five nineteen ten thirteen thirteen ninefivetwo thirteen seventeen sixteen eight zero eighteen sixteen zerotwotwo seven fifteen sixteen eighteen sixteen nineteen eight nineteen one seventeen fifteen one fifteen zerotenone seventeen fifteen three seven twelve eleven thirteen thirteenthirteen six eighteen sixten four fourteen eleven nineteen sixten four eleven twelve fifteen three sixfour zero eight four nineteen eight fivesix fifteen zero three zero eighteen sixteen seven four eight zero thirteen five nine three zero twelve five eleventwofour eleven zerotenone sixteen three fivetwo twelve thirteen eighteen twelve oneoneone twelve twotwo fourteen eighteen fivenine three twelve sixteen fivefive nineteen three twosixnine thirteen nineteen seven tensix three twelve eight seventeensix fifteen seven fourteen five eighteen three three fourteen nineteen eleven eleven one nineteen eleven three eighteen fourteen four sixteen thirteen seven seven twelve twelve sixtwo five thirteen five eight ten seven four sixteen eighteen foursix sixteen fourteen one nine threetwo zero fifteen zero eight fifteen twelve seventeen eleven sixfour eight eleven eighteen one eleven three sixteen eleven twonine fifteen eighteen ten fifteen two fifteen sixteen twosix fourteen fifteen nineteen sixteen sixteen three three nine ninetwonineonezeroninetenone eleven six three eleven zero three zerofourten eighteen seven one sixteen six nineteen sixfive nineteen eleven fiveonetwosix fourteen thirteen eighteen five nineteen fourteen onetwo twelve five eight zero thirteen seventeen one sevensixnine sixteen three fourteen sixteen nineteen nine twelve zero sixteen zero four eighteen one fourteen four three fourteen thirteen zero seven ten twelve eight ten four eleven nineteen twelve fifteen seven six eighteen three eleven three one sixteen nine four two five zeroseven nine eleven fifteen twelve eight tenfive five thirteen seven four seven seven seven thirteen four nine five fifteen eight two eleven fourteen thirteen zero eight eighteen ten four fourteen eighteen twelve fifteen four one sixteen nineteen two zero nine four nineteensixteen twelve eight sixteen eight thirteen seven eleven thirteen ten eighteen seven fifteen twelve five seventeen twelve tenzero seventeen five nineteen fivesixfourtwoone fourteen fifteen nineteen two eight twelve fiveonesix thirteen fifteen one seven nine nineteen threeeight four fifteen nine eleven three three seventeen eleven sixteen fourteen eighteen seven eleven eleven five sixteen two seven four thirteen eight sixteen fivetenten seven tennine seventeen zeroone fifteen sixteen twelve seven zero three seven two eighteen twelve eleventen sixteen one fifteen eight thirteen ten seventeen fifteen fourteen zero thirteen sixteen four seventeen seventeen thirteen seven fouronefive zero three fourteen fourteen ninefive fourteen seventeen seventeen eight oneone eighteen seventeen twelve two twelve eleven zero nineteen eleven thirteeneleven fifteen sixteen fourteen four seven seven eleven nine seven foursix fourteen nineteen nineteen seven nine eight two nineteen eleven seventeen four eighteen sixsixtwo three nine eleven nineteen seventeen sixzerosix three eleven three thirteen twelve fourten fifteentwelve seven two eight nineone fifteen one twelve four eleven seven five eight nineteen seventeen twelve thirteen ten seventeen eighteen seven eight seven fourteen twelve six nineteen ten thirteen sixteen ten seven ten seven fourteen eighteen zero zero eighteen twoonefourseven eighteen two three thirteen nineteen two thirteen two eleven seven eleven zero eighteen eighteen seventeen eighteen eight nineteen two nineteen seven seventeen eleven seven eighttentensixtwonine eight twelve four eleven three four seven eleven twotwosix thirteenfive twelve oneonezero fifteen onefourfive sixteen fifteen ten eighteen seven nineteen six fifteen eight onefour fifteen seventeen six twelve nineteen ten seventeen zero zero fourteen seven sixteen tenzero nineteen seven five thirteen four eleven five three eleveneight seven seventeen onetwo three zero three twelve three zero fifteen nine eight eight five eighteen eightsix fourteen seven eight seventeen fifteen thirteen twelve seventeen three twotwo twelve eleven seven seventeen ten seven fourteen six seventeen nineteen twelve eight nineteeneight sixteen seventeen eleven fourfour nine three eleven seventeen thirteen two zerotennine sixteen five threesix eighteen three thirteen zero sixteen one fifteen ten eighteen eleven seventeen seventeen fouronefour fourteen five nineteen fourteen fifteen fifteen fifteen fifteen twelveeleven twelve sixteen six fifteen seventeen eighteen five thirteen eleven twotenfive eleven twelve six eleven sixteen tenzero eighteen eleven fourteen eight twelve three fivetenten fourteen ten eleven two zero seventeen six seven eleven thirteen twelve thirteen zerotwo zerothirteen tenone fifteen eighttensix fourteen six eleven twelve seven three eleven five seventeen seventeen one twelve eight fourteen eleven seven one eleven seven twonine nine eleven seventeen seventeen nineteen five seven sixteen two three thirteen fifteen twelve seven fourthreetenzero three fifteen seventeen fivefourtenzero seven eleven sixteen seven twelve five nineteen six seven four zeroonefour thirteen fifteen seven eleven five fifteen fourteen fourteen one thirteen eleven seven seventeen nine eleven twelve fourteen tentwo zeroeleven fourteen fifteen fourteen six seven ninesixfiveone sixteen eleven fourteen nineteen seven one nineteen seven five seventeen fourteen eighteen eighteen five seven eight eleven eleven seven eleven eight nine eleven twelve fifteen seven seventeen ten eleven eleven thirteen three sixteeneightnineteeneighttwothirteennineteenfourthirteenfivetenthirteenthree hundred and fourty-six one hundred and thirtynine hundred and ninety -two ninety -onesix hundred and sixty-seven one hundred and twenty-four six hundred and twelvefour hundred and twenty-one nine hundred and seventy one hundred and fifty-seven thirteenfive hundred and seventy-two five hundred and seventy-four nine hundred and onefive hundred and tenthree hundred and sixty-one four hundred and seventeen seven hundred and fourty-seven four hundred and eighty-five seventy-twoone hundred and fourty-six four hundred and seventy-two one hundred and ninety -seven nine hundred and ninety -eight two hundred and fourty-five five hundred and thirty-sixtwo hundred and eighty-two five hundred and ninety -seven seven hundred and ninety -three eight hundred and thirty-five seven hundred and twosix hundred and seventysix hundred and sixteenseven hundred and thirty-seven three hundred and twenty-three nine hundred and eighty-two seventeenfive hundred and seventy-six one hundred and eightfive hundred and seventwo hundred and ninety -nine four hundred and ninety -four six hundred and seventy-two eight hundred and ninety -seven eight hundred and seventy-six seven hundred and eighty-eight three hundred and sixty-nine six hundred and fifty-sixone hundred and seventy-two four hundred and fourty-seven one hundredeight hundred and twenty eight hundred and twentyone hundred and twenty-three six hundred and seventy-eight three hundred and fifty-nine sixty-oneseven hundred and ninety -three one hundred and seventy-eight five hundred and ninety -four four hundred and ninesix hundred and seventy-five nine hundred and fifty-one four hundred and threeeight hundred and eighty-five five hundred and seventy-eight seven hundred and eightytwo hundred and sixtwo hundred and sixty-fivefifty-threefour hundred and fourty-two two hundred and eighty-seven four hundred and twenty-four three hundred and fourty-one nine hundred and sixty-eightsix hundred and fourty-seven two hundred and eighty-one four hundred and sixty-six four hundred and sixty-four nine hundred and fourty-two one hundred and sixty-eight eight hundred and sixty-six one hundred and seventy-one six hundred and ninety -six one hundred and thirty-nine one hundred and thirty-one four hundred and thirty-five one hundred and fifty-seven two hundred and eighty-three twenty-threeeight hundred and seventy-four five hundred and eightythree hundred and fiveseven hundred and fifty-eight fourtwo hundred and ninety -six sixty-nineseven hundred and eighteen four hundred and twoone hundred and fifty-five seven hundred and fifty-one three hundred and sixty-three two hundred and ninety -two three hundred and twentyone hundred and eighteen seven hundred and fourtyfourfive hundred and seventy-two three hundred and fifty-seven one hundred and fourty-six nineteenone hundred and seventeen nine hundred and seventy-six five hundred and tensix hundred and thirty-four four hundred and fifty-four twenty-threeone hundred and fourseven hundred and fourty-eightfive hundred and ninenine hundred and onefive hundred and twenty fourty-twoone hundred and sixty-three two hundred and seventy-seven five hundred and sixteentwo hundred and twelveone hundred and ninety -two seven hundred and twentysix hundred and eighty-eight five hundred and fifty-one three hundred and seventy-four nine hundred and eighty-six one hundred and fifty-one seven hundred and fourty-five three hundred and fourty-one five hundred and ninety -two four hundred and threeseven hundred and fourty-eight three hundred and fourty-eight one hundred and sixty-eight seven hundred and fifty-two thirty-oneone hundred and fourty-three four hundred and sixty-sixtwo hundred and seventytwo hundred and sixty-sixfive hundred and onesix hundred and ninety -three six hundred and fourty-eight seven hundred and twenty-three eight hundred and twelvefour hundred and fourtythree hundred and fifty-sixtwo hundred and sixty-three four hundred and eightynine hundredeight hundred and thirty-five seven hundred and eighty-three nine hundred and twentytwo hundred and twenty-one five hundred and fourty-two two hundred and fifteennine hundred and threeone hundred and eighty-sixone hundred and twenty-one four hundred and eightfour hundred and eighty-four three hundred and sixty-four nine hundred and ninety -six five hundred and seventy-three eight hundred and fourone hundred and thirty-ninefive hundred and twenty-three nine hundred and eleven three hundred and thirtyone hundred and sixty-twofour hundred and sixty-five three hundred and sixty-seven three hundred and ninety -six ninety -ninesix hundred and eighty-five seven hundred and eighty-nine eight hundred and fourty-nine one hundred and thirty-one three hundred and fourty-three one hundred and ninety -five three hundred and seventy-six three hundred and thirty-two one hundred and fifty-sixsix hundred and thirty-four seven hundred and seventy-six sixtytwo hundred and seventwenty-onefour hundred and fifty-ninenine hundred and sixty-four seven hundred and sixtyone hundred and fivefifty-fourseven hundred and eighty-two seven hundred and sixty-seven five hundred and seventy-three nine hundred and seventy-eight four hundred and seventy-nine one hundred and fourty-twotwo hundred and eighty-four one hundred and thirty-onefifty-nineone hundred and teneight hundredthree hundred and eleven seven hundred and ninety -two six hundred and eighty-five seven hundred and oneone hundred and sixty-seven three hundred and sixteenfour hundred and ninety -three seven hundred and thirty-four nine hundred and fourty-two nine hundred and eighty-eight eight hundred and twelvetwo hundred and seventeenone hundred and fourty-five nine hundred and sixty-five nine hundred and sixty-one two hundred and thirty-nine one hundred and sixtwenty-eightnine hundred and fourty-one one hundred and eighty-seven three hundred and fourty-eight one hundred and sevenseven hundred and ninety -seven four hundred and thirty-three two hundred and seventy-seven five hundred and fifty-ninesix hundred and sixty-sixsix hundred and seventy-four fourtysix hundred and ninety -seven one hundred and eighteight hundred and fiveeight hundred and sixty-eight two hundred and nineteen seventy-twoseven hundred and ninety -five seven hundred and twelvesix hundred and thirty-seventwo hundred and twenty-six nine hundred and thirty-two nine hundred and sixty-six eight hundred and fifty-four seven hundred and ninety -six four hundred and twenty-seven nine hundred and fifty-two five hundred and ninety -four six hundred and fourty-nine nine hundred and fifty-six seven hundred and sixteenfive hundred and fifty-two seven hundred and ninety -seven eight hundred and sixty-seven six hundred and eighty-onefour hundred and twenty-two seven hundred and thirtyfive hundred and fifty-seven eight hundred and seventy-four four hundred and fifty-nine sixty-foursix hundred and eighty-foursix hundred and fifty-sixfour hundred and seventyone hundred and thirty-one eight hundred and seventy-eight seven hundred and seventy-two six hundred and fourty-seven five hundred and fifty-seven nine hundred and fourty seven hundred and eighty-nine eight hundred and sixteen three hundred and twenty-eight two hundred and ninety -one seven hundred and ninety -nine six hundred and ninety -two one hundred and ninety -six two hundred and sixty-two eight hundred and fifty-seven four hundred and ninety -two one hundred and twenty-five five hundred and eighty-fivesix hundred and fourty-oneninety -eighteight hundred and twenty-one four hundred and seventy-nine one hundred and eighty-seven five hundred and fourty-six sixty-twotwo hundred and seventy-two ninetwo hundred and sixfour hundred and fiftythree hundred and seventy-nine two hundred and thirty-sixtwo hundred and twenty-five three hundred and twenty-one five hundred and seventy-four eight hundred and seventy-nine thirty-onefour hundred and thirty-three seven hundred and fourty-nine six hundred and seventy-nine two hundred and fourty-two three hundred and fourty-two seven hundred and thirty-one six hundred and twenty-three five hundred and seventy-seven seven hundred and twenty-two seven hundred and twenty-seven nine hundred and ninety -three one hundred and fourty-four seven hundred and twenty-three seven hundred and eighty-eight two hundred and fourty-four fifty-ninefour hundred and twenty-one fourty-twoseven hundred and fourty-three five hundred and ninety -three eight hundred and fourtyeight hundred and ninety -six nine hundred and teneight hundred and twenty-two fourty-ninethree hundred and sixty-seven seven hundred and sixty-oneseven hundred and fourty-eight one hundred and fourteenthree hundred and ninety -three seven hundred and seventy-one six hundred and ninety -nine five hundred and sixty-threesix hundred and thirty-eight eight hundred and fourty-nine five hundred and ninety -fivesix hundred and ninety -two three hundred and ninety -five four hundred and eighty-seven three hundred and threethirtyfour hundred and ninety -eight nine hundred and seventy-one seven hundred and twenty-eight six hundred and eighty-four seven hundred and eighty-nine eight hundred and fourty-six nine hundred and seventy-eight one hundred and fourty-four four hundred and ninety -four three hundred and fifteenfive hundred and sevensix hundred and thirty-fourone hundred and fifty-onefive hundred and fiftyseven hundred and onesixteenfive hundred and eighty-five four hundred and sixty-sixeight hundred and nineseven hundred and seventy-eight nine hundred and ninety -three three hundred and fourtysix hundred and fifty-fourthree hundred and thirtytwo hundred and twenty-three two hundred and fifty-threesix hundred and fourty-oneone hundred and thirty-seven one hundred and fourtwo hundred and ninety -six ninety -sevenfive hundred and thirty-four nine hundred and seventeen fourty-ninenine hundred and eighteen three hundred and seventy-one one hundred and ninety -five three hundred and eleven eight hundred and ninety -three four hundred and ninefive hundred and eighty-five five hundred and twenty-six two hundred and tenone hundred and twenty-nine five hundred and fifty-four two hundred and seventy-eight four hundred and fifteenfour hundred and eighty-two four hundred and thirty-nine three hundred and twenty-three seven hundred and seventy-five nine hundred and eighty-four nine hundred and thirty-three six hundred and twenty-two three hundred and twenty-two sixteenthree hundred and ninetysix hundred and fifty-six three hundred and fifty-six three hundred and fifty-six seven hundred and seventeen four hundred and seventy-nine one hundred and eighty-four six hundred and ninetyeight hundred and fiftysix hundred and seventeentwo hundred and sixty-three nine hundred and three three hundred and sixty-three four hundred and fifty-twofive hundred and twenty-seven two hundred and eighty-twoone hundred and eighty-seven two hundred and seventy-five eight hundred and sixty-six nine hundred and twenty-four six hundred and seventyfive hundred and eighty-four fifty-oneone hundred and seventy-nine five hundred and thirty-six fourtyfour hundred and ninety -five six hundred and seventy-three one hundred and fifty-two three hundred and thirty-eight two hundred and twenty-three nine hundred and twenty-two four hundred and fourty-one one hundred and sixty-twoone hundred and eighty-nine six hundred and nineteenfour hundred and sixtysix hundred and seventyone hundred and seventy-nine one hundred and sixty-three five hundred and ninety -three elevennine hundred and twenty-eight three hundred and thirty-five sixty-threesevenone hundred and thirty-two eight hundred and ninety -six fiveeight hundred and sixsix hundred and ninetwo hundred and seventy-seven nine hundred and ninety -five sixty-fivenine hundred and eighteen seven hundred and fourty-four five hundred and nineteentwo hundred and twenty-six seventy-seveneight hundred and sixteennine hundred and twoeight hundred and seventy-seven eight hundred and thirty-six twenty-sixtwo hundred and ninety -four two hundred and sixty-twofive hundred and eighttwo hundred and sixty-seven sixty-oneeight hundred and thirty-eight three hundred and seventy-five one hundred and fifty-nine three hundred and eighty-two eight hundred and twelveeight hundred and twentythirty-oneseventeensix hundred and fourthree hundred and twelvefive hundred and eighteen seven hundred and fiveeight hundred and thirty-two seven hundred and fifty-two seven hundred and ninety -eight five hundred and twenty-three three hundred and thirty-six one hundred and fifteenthree hundred and seventynine hundred and nineteen nine hundred and tennine hundred and two sixteensix hundred and sixty-onethirty-sixtwo hundred and fourty-sixfour hundred and sixtytwo hundred and seventeentwo hundred and sixtynine hundred and eighty-five one hundred and fifty-six seven hundred and eighty-four one hundred and thirty-threefive hundred and twenty-three five hundred and twenty-four seven hundred and fourty-six four hundred and fifty-foursix hundred and sixty-eightnine hundred and sixty-seven three hundred and sixty-eight twenty-fivetwo hundred and ninety -three one hundred and ninety -nine two hundred and thirty-two eight hundred and fifteensix hundred and fourty-four seven hundred and fiftynine hundred and seventy-eight three hundred and ninety -five two hundred and sevensix hundred and twenty-sixnine hundred and ninety -eight two hundred and sixty-oneone hundred and seventy-five one hundred and eighty-nine three hundred and seventy-eight one hundred and eighty-eight twenty-twofive hundred and eighteeneight hundred and ninety -one three hundred and eighty-two four hundred and sevennine hundred and ninety -six three hundred and fourty-nine five hundred and ninety -five nine hundred and nineteen three hundred and fiveseven hundred and fourty-seven one hundred and ninety -three three hundred and tenfive hundred and ninety -seven three hundred and eighteen three hundred and thirty-five nine hundred and seventeen six hundred and thirty-sixnine hundred and thirtyone hundred and twenty-eight two hundred and sixty-seven three hundred and fourty-six six hundred and nineteenfive hundred and seventy-seven three hundred and eighty three hundred and seventy-two nine hundred and oneseven hundred and fourty-one one hundred and eighty-four eight hundred and thirteenfour hundred and twenty-three two hundred and thirteen seven hundred and twelvesix hundred and ninety -four one hundred and fourty-seven three hundred and twenty-seven three hundred and seventy-six eight hundredeight hundred and sixty-five four hundred and sixthree hundred and twentyfour hundred and fifty-five three hundred and twenty-three three hundred and nineteen nine hundred and sixty-three one hundred and seventy-two six hundred and sixty-eight eightfour hundred and ninety -six seventy-sixthree hundred and ninety -two six hundred and sixty-six seven hundred and tenthree hundred and sixty-five five hundred and fourtytwo hundred and fifty-one three hundred and thirty-seven four hundred and eighty-one five hundred and seventy-three seven hundred and eighty-eight six hundred and sixty-eight two hundred and seventy-threeseven hundred and sixty-one eight hundred and thirty-seven two hundred and twenty-six four hundred and sixty-two two hundred and fourty-four five hundred and twenty-six two hundred and twenty-five one hundred and fifty-nine sixty-eightfour hundred and ninety seven hundred and thirty-five six hundred and fifty-two eight hundred and eighty-one fifty-fourtwo hundred and seventy-five one hundred and seventy-four two hundred and threefive hundred and seventy-eight four hundred and fourtysixty-twoone hundred and twoeight hundred and fiftyfive hundred and eighty-six eight hundred and fourty-one twenty-fivefive hundred and eighty-one two hundred and sixnine hundred and fourty-five four hundred and eighteen five hundred and ninety -three three hundred and twelvesix hundred and fifty-four four hundred and nineteen eight hundred and fifty-eight seventy-twotwo hundred and twenty-eight seven hundred and fourteen one hundred and seventy-nine three hundred and eighty-six six hundred and eighteensix hundred and tensix hundred and fifty-nine four hundred and eighty-twosix hundred and eightseven hundred and seventy-nine three hundred and ninety -seven nine hundred and twenty-seven nine hundred and sixty-seven six hundred and tensix hundred and twenty-onefour hundred and thirtynine hundred and onenine hundred and seventy-eight three hundred and eighty-five five hundred and twenty-seven five hundred and nineteenthree hundred and nineteenfifty-twosix hundred and sixteenfive hundred and fifty-onesix hundred and twenty-eight seven hundred and fifteenone hundred and ninety -seven seven hundred and sixty-three six hundred and sixty-fourfour hundred and fourty-three seventy-threeseven hundred and nineteenone hundred and eighty-seven six hundred and seventy-one one hundred and fourteenone hundred and sixty-eight three hundred and ninety -nine ninethree hundred and seventy-four five hundred and thirty-sixnine hundred and seventy-three nine hundred and thirty-one three hundred and twenty-seven three hundred and ninetytwo hundred and fourty-four two hundred and fourty-twofive hundred and ninetyseven hundred and sixtyone hundred and twelveseven hundred and sixtyseven hundred and eighty-one four hundred and eighty-four five hundred and fourty-five one hundred and sevenseven hundred and thirty-nine nine hundred and seventy-three eighty-eightfive hundred and thirty-fourfive hundred and ninety -fivesix hundred and sixty-eightone hundred and seventy-three three hundred and fiftytwo hundred and sixty-one seven hundred and thirtyfour hundred and ninety -four six hundred and thirty-eightone hundred and onesix hundred and threefifty-eighttwo hundred and nineseven hundred and twenty-six eight hundredninety -nineeight hundred and ninety -eight seven hundred and eighty-seven two hundred and fifty-three three hundred and fourty-eight nine hundred and fifty-four three hundred and ninety -five five hundred and ninety -one seven hundred and fourtynine hundred and fivefour hundred and eightythree hundred and thirty-three fourty-twoeight hundred and sixty-three nine hundred and fifty-three three hundred and fifty-two sixty-onefifty-fourthree hundred and fourty-three six hundred and ninenine hundred and twenty-threeone hundred and seventy-four nine hundred and fourteensix hundred and ninety -two seven hundred and nineseven hundred and ninety ninety -threefive hundred and ninety -five one hundred and thirty-one sixty-sevennine hundred and fourty-three seven hundred and fourty-three six hundred and ninety -onetwo hundred and ninety -eight three hundred and fourty-two thirteenfour hundred and sixty-fivefive hundred and fourty-eight two hundred and eighty-six nine hundred and seventy-three thirty-fiveseven hundred and twelveeight hundred and fourty-nine five hundred and eighteenfifty-eightfive hundred and ninety -sixtwo hundred and twelveninety -twofour hundred and sixty-fourtwo hundred and fifty-eight seven hundred and fifty-onefive hundred and seventy-eight six hundred and thirty-seven seven hundred and ninefive hundred and sixty-sixone hundred and thirty-oneone hundred and seventy-two six hundred and fourty-fivetwo hundred and thirteensix hundred and thirteenseven hundred and seventy-three four hundred and sixty-seven four hundred and fourteennine hundred and thirty-two。
C语言把数字转换为字符串的函数
C语⾔把数字转换为字符串的函数C语⾔itoa()函数和atoi()函数详解(整数转字符C实现)C语⾔提供了⼏个标准库函数，可以将任意类型(整型、长整型、浮点型等)的数字转换为字符串。
1.int/float to string/array:C语⾔提供了⼏个标准库函数，可以将任意类型(整型、长整型、浮点型等)的数字转换为字符串，下⾯列举了各函数的⽅法及其说明。
● itoa()：将整型值转换为字符串。
● ltoa()：将长整型值转换为字符串。
● ultoa()：将⽆符号长整型值转换为字符串。
● gcvt()：将浮点型数转换为字符串，取四舍五⼊。
● ecvt()：将双精度浮点型值转换为字符串，转换结果中不包含⼗进制⼩数点。
● fcvt()：指定位数为转换精度，其余同ecvt()。
除此外，还可以使⽤sprintf系列函数把数字转换成字符串，其⽐itoa()系列函数运⾏速度慢2. string/array to int/floatC/C++语⾔提供了⼏个标准库函数，可以将字符串转换为任意类型(整型、长整型、浮点型等)。
● atof()：将字符串转换为双精度浮点型值。
● atoi()：将字符串转换为整型值。
● atol()：将字符串转换为长整型值。
● strtod()：将字符串转换为双精度浮点型值，并报告不能被转换的所有剩余数字。
● strtol()：将字符串转换为长整值，并报告不能被转换的所有剩余数字。
● strtoul()：将字符串转换为⽆符号长整型值，并报告不能被转换的所有剩余数字。
这⾥写⼀个常⽤的转换使⽤⽅式#include<stdio.h>#include<stdlib.h>void num_to_str(){int a = 10086;char buff[10] = {0};itoa(a,buff,10);//将a以10进制的形式写⼊buff中printf("%s\n", buff);}void str_to_num(){char *p = "10001";printf("%d\n", atoi(p));//atoi直接返回整形转换后的数据}int main(){num_to_str();str_to_num();return 0;}这⾥需要注意的是，atoi和itoa均为windows系统下stdlib.h⽂件内的库函数，因此，如果在Linux系统即使包含stdlib.h这个头⽂件，编译时仍然会提⽰这两个函数没有定义过。
自己动手写C语言浮点数转换字符串函数
⾃⼰动⼿写C语⾔浮点数转换字符串函数前⼏天，应⼀个⼩友要求，写了⼏个字符串转换函数帮助其进⾏语⾔学习，⾃觉其中的⼏个函数还⽐较满意，故发布在此，可供初学者参考。
浮点数转换字符串函数说简单也简单，说⿇烦，也够烦⼼的，关键看你如何写了。
简单点的⼏⼗⾏代码就⾏，复杂点的恐怕就的⼏百⾏代码了。
如果还要考虑移植性、可读性甚⾄可维护性等就更⿇烦的了。
我⼀贯认为，⼀些事务性的项⽬应着重考虑移植性、可读性和可维护性等，⽽常⽤的带点系统性质的函数代码就应该以执⾏效率为主。
本⽂的浮点数转换字符串函数还是⽐较复杂的，基本可算得上较低层次的转换。
由于我已经习惯了⽤BCB写C/C++代码，因此我写的浮点数转换字符串函数是80位扩展精度浮点数的，但那个⼩友拿回去试了⼀下，说他⽤的VC不⽀持80位扩展精度浮点数，虽然能定义long double变量，但实际上还是64位的，我只好⼜重写了⼀个64位双精度浮点数的，2个版本使⽤条件编译，这也算得上是移植性吧，呵呵。
下⾯是浮点数转换字符串函数的全部代码：#define USE_EXTENDED/**************************************************************************** 定义浮点数转换字符串结构 ****************************************************************************/typedef struct{SHORT exponent; /* 指数（整数位数） */BYTE negative; /* 负数（0正，1负）*/CHAR digits[21]; /* ⼗进制整数字串 */}FloatRec;#define F_DEFDECIMALS 6#define F_MAXDECIMALS 100#ifdef USE_EXTENDED#define F_MAXPRECISION 19#define F_CONEXPONENT 0x3ffftypedef long double EXTENDED, *PExtended, *PEXTENDED;#include <pshpack2.h>typedef struct{UINT64 mantissa;USHORT exponent;}_Extended;#include <poppack.h>static CONST _Extended _tab0[] ={{0x8000000000000000, 0x3FFF}, /* 10**0 */{0xA000000000000000, 0x4002}, /* 10**1 */{0xC800000000000000, 0x4005}, /* 10**2 */{0xFA00000000000000, 0x4008}, /* 10**3 */{0x9C40000000000000, 0x400C}, /* 10**4 */{0xC350000000000000, 0x400F}, /* 10**5 */{0xF424000000000000, 0x4012}, /* 10**6 */{0x9896800000000000, 0x4016}, /* 10**7 */{0xBEBC200000000000, 0x4019}, /* 10**8 */{0xEE6B280000000000, 0x401C}, /* 10**9 */{0x9502F90000000000, 0x4020}, /* 10**10 */{0xBA43B74000000000, 0x4023}, /* 10**11 */{0xE8D4A51000000000, 0x4026}, /* 10**12 */{0x9184E72A00000000, 0x402A}, /* 10**13 */{0xB5E620F480000000, 0x402D}, /* 10**14 */{0xE35FA931A0000000, 0x4030}, /* 10**15 */{0x8E1BC9BF04000000, 0x4034}, /* 10**16 */{0xB1A2BC2EC5000000, 0x4037}, /* 10**17 */{0xDE0B6B3A76400000, 0x403A}, /* 10**18 */{0x8AC7230489E80000, 0x403E}, /* 10**19 */{0xAD78EBC5AC620000, 0x4041}, /* 10**20 */{0xD8D726B7177A8000, 0x4044}, /* 10**21 */{0x878678326EAC9000, 0x4048}, /* 10**22 */{0xA968163F0A57B400, 0x404B}, /* 10**23 */{0xD3C21BCECCEDA100, 0x404E}, /* 10**24 */{0x84595161401484A0, 0x4052}, /* 10**25 */{0xA56FA5B99019A5C8, 0x4055}, /* 10**26 */{0xCECB8F27F4200F3A, 0x4058}, /* 10**27 */{0x813F3978F8940984, 0x405C}, /* 10**28 */{0xA18F07D736B90BE5, 0x405F}, /* 10**29 */{0xC9F2C9CD04674EDF, 0x4062}, /* 10**30 */{0xFC6F7C4045812296, 0x4065} /* 10**31 */};static CONST _Extended _tab1[] ={{0x9DC5ADA82B70B59E, 0x4069}, /* 10**32 */{0xC2781F49FFCFA6D5, 0x40D3}, /* 10**64 */{0xC2781F49FFCFA6D5, 0x40D3}, /* 10**64 */{0xEFB3AB16C59B14A3, 0x413D}, /* 10**96 */{0x93BA47C980E98CE0, 0x41A8}, /* 10**128 */{0xB616A12B7FE617AA, 0x4212}, /* 10**160 */{0xE070F78D3927556B, 0x427C}, /* 10**192 */{0x8A5296FFE33CC930, 0x42E7}, /* 10**224 */{0xAA7EEBFB9DF9DE8E, 0x4351}, /* 10**256 */{0xD226FC195C6A2F8C, 0x43BB}, /* 10**288 */{0x81842F29F2CCE376, 0x4426}, /* 10**320 */{0x9FA42700DB900AD2, 0x4490}, /* 10**352 */{0xC4C5E310AEF8AA17, 0x44FA}, /* 10**384 */{0xF28A9C07E9B09C59, 0x4564}, /* 10**416 */{0x957A4AE1EBF7F3D4, 0x45CF}, /* 10**448 */{0xB83ED8DC0795A262, 0x4639} /* 10**480 */};static CONST _Extended _tab2[] ={{0xE319A0AEA60E91C7, 0x46A3}, /* 10**512 */{0xC976758681750C17, 0x4D48}, /* 10**1024 */{0xB2B8353B3993A7E4, 0x53ED}, /* 10**1536 */{0x9E8B3B5DC53D5DE5, 0x5A92}, /* 10**2048 */{0x8CA554C020A1F0A6, 0x6137}, /* 10**2560 */{0xF9895D25D88B5A8B, 0x67DB}, /* 10**3072 */{0xDD5DC8A2BF27F3F8, 0x6E80}, /* 10**3584 */{0xC46052028A20979B, 0x7525}, /* 10**4096 */{0xAE3511626ED559F0, 0x7BCA} /* 10**4608 */};static CONST EXTENDED _conPrec = 1E19;#else// USE_EXTENDED#define F_MAXPRECISION 17#define F_CONEXPONENT 0x03fftypedef double EXTENDED, *PExtended, *PEXTENDED; static CONST UINT64 _tab0[] ={{0x3FF0000000000000}, /* 10**0 */{0x4024000000000000}, /* 10**1 */{0x4059000000000000}, /* 10**2 */{0x408F400000000000}, /* 10**3 */{0x40C3880000000000}, /* 10**4 */{0x40F86A0000000000}, /* 10**5 */{0x412E848000000000}, /* 10**6 */{0x416312D000000000}, /* 10**7 */{0x4197D78400000000}, /* 10**8 */{0x41CDCD6500000000}, /* 10**9 */{0x4202A05F20000000}, /* 10**10 */{0x42374876E8000000}, /* 10**11 */{0x426D1A94A2000000}, /* 10**12 */{0x42A2309CE5400000}, /* 10**13 */{0x42D6BCC41E900000}, /* 10**14 */{0x430C6BF526340000}, /* 10**15 */{0x4341C37937E08000}, /* 10**16 */{0x4376345785D8A000}, /* 10**17 */{0x43ABC16D674EC800}, /* 10**18 */{0x43E158E460913D00}, /* 10**19 */{0x4415AF1D78B58C40}, /* 10**20 */{0x444B1AE4D6E2EF50}, /* 10**21 */{0x4480F0CF064DD592}, /* 10**22 */{0x44B52D02C7E14AF7}, /* 10**23 */{0x44EA784379D99DB4}, /* 10**24 */{0x45208B2A2C280291}, /* 10**25 */{0x4554ADF4B7320335}, /* 10**26 */{0x4589D971E4FE8402}, /* 10**27 */{0x45C027E72F1F1281}, /* 10**28 */{0x45F431E0FAE6D722}, /* 10**29 */{0x46293E5939A08CEA}, /* 10**30 */{0x465F8DEF8808B024} /* 10**31 */};static CONST UINT64 _tab1[] ={{0x4693B8B5B5056E17}, /* 10**32 */{0x4D384F03E93FF9F5}, /* 10**64 */{0x53DDF67562D8B363}, /* 10**96 */{0x5A827748F9301D32}, /* 10**128 */{0x6126C2D4256FFCC3}, /* 10**160 */{0x67CC0E1EF1A724EB}, /* 10**192 */{0x6E714A52DFFC679A}, /* 10**224 */{0x75154FDD7F73BF3C}, /* 10**256 */{0x7BBA44DF832B8D46}, /* 10**288 */};static CONST EXTENDED _conPrec = 1E17;#endif// !USE_EXTENDED#endif// !USE_EXTENDEDstatic CONST UINT64 _cvttab[F_MAXPRECISION] ={#ifdef USE_EXTENDED0xDE0B6B3A7640000, 0x16345785D8A0000,#endif0x02386F26FC10000, 0x0038D7EA4C68000, 0x0005AF3107A4000, 0x00009184E72A000, 0x00000E8D4A51000, 0x00000174876E800, 0x0000002540BE400, 0x00000003B9ACA00, 0x000000005F5E100, 0x000000000989680, 0x0000000000F4240, 0x0000000000186A0, 0x000000000002710, 0x0000000000003E8, 0x000000000000064, 0x00000000000000A, 0x000000000000001};#define DECIMAL_EXP(exponent) ((((exponent - F_CONEXPONENT) * 0x4d10) >> 16) + 1) static VOID AdjFloatDigits(UINT64 value, INT precision, INT decimals, FloatRec *rec){INT i;// value是F_MAXPRECISION位⼗进制整数，故从最⾼位开始转换为数字串for (i = 0; value; i ++){rec->digits[i] = (CHAR)((value / _cvttab[i]) | 0x30);value %= _cvttab[i];}memset(rec->digits + i, 0, F_MAXPRECISION - i);// 下⾯对数字串作精度处理// 如果总的精度⼩于0，数字串为空串，该数字转换为'0'if ((i = (rec->exponent + decimals)) < 0){rec->exponent = rec->negative = rec->digits[0] = 0;return;}if (i > precision) i = precision;// 如果精度位数⼩于18，同时该位⼤于等于'5'，四舍五⼊if (i < F_MAXPRECISION && rec->digits[i] >= '5'){do{rec->digits[i --] = 0;rec->digits[i] ++;}while (i >= 0 && rec->digits[i] > '9');if (i < 0){rec->digits[0] = '1';rec->exponent ++;}}// 否则，去掉数字串尾部多余的'0'else{if (i > F_MAXPRECISION) i = F_MAXPRECISION;do rec->digits[i --] = 0;while (i >= 0 && rec->digits[i] == '0');if (i < 0) rec->negative = 0;}}#ifdef USE_EXTENDED// 解析扩展精度浮点数为⼗进制字符串，并存⼊浮点数记录中// 参数：浮点数指针，精度，⼩数位，浮点数记录VOID FloatResolve(PEXTENDED pvalue, INT precision, INT decimals, FloatRec *rec){INT power;EXTENDED val;// 79位：扩展精度浮点数符号位rec->negative = ((_Extended*)pvalue)->exponent >> 15;// 64-78位：扩展精度浮点数阶码(阶码 - 0x3fff = ⼆进制指数)rec->exponent = ((_Extended*)pvalue)->exponent & 0x7fff;if (!rec->exponent) // *pvalue = 0{rec->negative = rec->digits[0] = 0;return;}if (rec->exponent == 0x7fff)// *pvalue = nan or inf{if (!((*(LPBYTE)pvalue + 7) & 0x80) || !(*(PUINT64)pvalue & 0x7fffffffffffffff)){lstrcpyA(rec->digits, "INF");}else{rec->exponent ++;rec->negative = 0;lstrcpyA(rec->digits, "NAN");}return;}// 阶码转换为⼗进制指数// 阶码转换为⼗进制指数rec->exponent = DECIMAL_EXP(rec->exponent);// 0-63位：扩展精度浮点数尾数转换成F_MAXPRECISION位⼗进制浮点整数格式val = *pvalue;*((LPBYTE)&val + 9) &= 0x7f;// val = fabs(*pvalue)power = F_MAXPRECISION - rec->exponent;if (power > 0) // if (power > 0) val *= (10**power){val *= *(PEXTENDED)&_tab0[power & 31];power >>= 5; // power /= 32;if (power){if (power & 15)val *= *(PEXTENDED)&_tab1[(power & 15) - 1];power >>= 4; // power /= 16;if (power)val *= *(PEXTENDED)&_tab2[power - 1];}}else if (power < 0) // if (power < 0) val /= (10**power){power = -power;val /= *(PEXTENDED)&_tab0[power & 31];power >>= 5; // power /= 32;if (power){if (power & 15)val /= *(PEXTENDED)&_tab1[(power & 15) - 1];power >>= 4; // power /= 16;if (power)val /= *(PEXTENDED)&_tab2[power - 1];}}val += 0.5; // 四舍五⼊if (val >= _conPrec){val /= 10;rec->exponent ++;}// 调整并转换扩展精度浮点数尾数的整数部分rec->digitsAdjFloatDigits(*(PUINT64)&val >> ((((_Extended*)&val)->exponent - 0x3fff) ^ 0x3f), precision, decimals, rec);}#else// USE_EXTENDED// 解析双精度浮点数为⼗进制字符串，并存⼊浮点数记录中// 参数：浮点数指针，精度，⼩数位，浮点数记录VOID FloatResolve(PEXTENDED pvalue, INT precision, INT decimals, FloatRec *rec) {INT power;EXTENDED val;// 63位：双精度浮点数符号位rec->negative = *((LPBYTE)pvalue + 7) >> 7;// 52-62位：双精度浮点数阶码(阶码 - 0x3ff = ⼆进制指数)rec->exponent = (*(PUINT64)pvalue >> 52) & 0x7ff;if (!rec->exponent) // *pvalue = 0{rec->negative = rec->digits[0] = 0;return;}if (rec->exponent == 0x7ff)// *pvalue = nan or inf{if ((*(PUINT64)pvalue & 0xfffffffffffff) == 0){lstrcpyA(rec->digits, "INF");}else{rec->exponent ++;rec->negative = 0;lstrcpyA(rec->digits, "NAN");}return;}// 阶码转换为⼗进制指数rec->exponent = DECIMAL_EXP(rec->exponent);// 0-51位：双精度浮点数尾数转换成F_MAXPRECISION位⼗进制浮点整数格式val = *pvalue;*((LPBYTE)&val + 7) &= 0x7f;// val = fabs(*pvalue)power = F_MAXPRECISION - rec->exponent;if (power > 0) // if (power > 0) val *= (10**power){val *= *(PEXTENDED)&_tab0[power & 31];power >>= 5; // power /= 32;if (power)val *= *(PEXTENDED)&_tab1[power - 1];}else if (power < 0) // if (power < 0) val /= (10**power)else if (power < 0) // if (power < 0) val /= (10**power){power = -power;val /= *(PEXTENDED)&_tab0[power & 31];power >>= 5; // power /= 32;if (power)val /= *(PEXTENDED)&_tab1[power - 1];}// 16位⼗进制浮点整数四舍五⼊val += 0.5;if (val >= _conPrec){val /= 10;rec->exponent ++;}// 调整并转换扩展精度浮点数尾数的整数部分rec->digits// 清除52-63位，加隐藏的⾼位，F_MAXPRECISION=17，⾼位超过52位，所以左移 AdjFloatDigits(((*(PUINT64)&val & 0x000fffffffffffff) | 0x0010000000000000) <<-(52 - ((*(PUINT64)&val >> 52) - 0x3ff)), precision, decimals, rec);}#endif// !USE_EXTENDED// 输出指数字符串到buffer，返回指数字符串长度INT PutExponent(LPSTR buffer, CONST FloatRec *rec){LPSTR p = buffer;INT e, exp = rec->digits[0]? rec->exponent - 1 : 0;*p ++ = rec->negative & 0x80? 'E' : 'e';if (exp < 0){exp = -exp;*p ++ = '-';}else *p ++ = '+';if ((e = (exp / 1000)) != 0){*p ++ = e + 0x30;exp %= 1000;}*p ++ = exp / 100 + 0x30;exp %= 100;*(PUSHORT)p = (((exp % 10) << 8) | (exp / 10)) + 0x3030;return (INT)(p - buffer + 2);}// 浮点数转换为字符串。
c语言无精度损失的字符串转浮点 -回复
c语言无精度损失的字符串转浮点-回复C语言是一种广泛应用于计算机编程的高级编程语言，它提供了丰富的功能和灵活的语法使得开发者们能够在不同的领域中构建复杂的应用程序。
其中，字符串转浮点数是一个常见的需求，我们希望能够准确地将一个字符串表示的数值转换成相应的浮点数。
然而，由于计算机内部数字的存储和计算方式，存在着浮点数精度损失的问题。
这意味着对于极大或极小的浮点数，或者小数位数很多的浮点数，转换后的结果可能会出现一些不准确的情况。
为了解决这个问题，我们需要采用一种能够保持精度的方法来进行字符串到浮点数的转换。
以下是一种C语言中无精度损失的字符串转浮点数的步骤：步骤1：检查输入字符串的合法性在进行字符串到浮点数的转换之前，我们需要先对输入字符串进行一些合法性检查。
例如，确保字符串不为空、不含有非法字符，以及符合浮点数的表示规则（包括小数点、科学计数法等）。
如果字符串不满足这些条件，我们需要提前对错误情况进行处理，以免后续的转换过程无法进行。
步骤2：拆分整数部分和小数部分通常，一个浮点数由整数部分和小数部分组成。
我们需要将输入字符串按照小数点进行拆分，得到整数部分和小数部分的字符串。
对于没有小数部分的情况，我们可以使用默认值0。
步骤3：将整数部分和小数部分转换成相应的数值在这一步中，我们需要将整数部分和小数部分的字符串转换成相应的数值。
对于整数部分，可以使用atoi函数将其转换成整数；对于小数部分，可以先计算其长度，然后按字符进行逐位转换，并通过累加得到相应的数值。
步骤4：根据小数点位置进行数值的调整在步骤3中得到的数值仅仅是整数部分和小数部分转换后得出的两个独立的数值。
由于浮点数的特殊存储方式，我们需要根据小数点的位置来将这两个数值进行合并，并得到最终的浮点数。
通常，我们可以通过将小数部分的数值除以10的幂次方来进行调整。
步骤5：处理其他特殊情况在具体实现过程中，我们还需要考虑一些特殊情况的处理，例如科学计数法表示的浮点数、负数的处理等。
十六进制转floatc语言
十六进制转floatc语言在计算机科学中，数字的表示形式有很多种，其中包括十进制、二进制、八进制和十六进制等。
而在C语言中，我们通常使用十六进制来表示浮点数。
那么，如何将一个十六进制数转换成浮点数呢？我们需要了解浮点数的表示方式。
在计算机中，浮点数通常由符号位、指数位和尾数位组成。
符号位用来表示正负号，指数位用来表示数值的大小，而尾数位则用来表示数值的精度。
接下来，我们来看一下具体的转换方法。
假设我们有一个十六进制数0x40490FDB，我们希望将其转换成浮点数。
首先，我们需要将这个十六进制数转换成二进制数。
这可以通过将每个十六进制数位转换成对应的四位二进制数来实现。
例如，0x4可以转换成二进制数0100，0x0可以转换成二进制数0000，以此类推，最终我们得到二进制数01000000100100001000111111011011。
接下来，我们需要确定符号位、指数位和尾数位的取值。
在IEEE 754标准中，浮点数的符号位占据了最高位，0表示正数，1表示负数。
接下来的8位用来表示指数位，而剩下的23位用来表示尾数位。
在上面的例子中，符号位为0，指数位为10000001，尾数位为00100001000111111011011。
接下来，我们需要将指数位和尾数位转换成十进制数。
指数位的转换方法是将其减去一个固定值，然后再将结果转换成十进制数。
在IEEE 754标准中，这个固定值为127。
所以，我们的指数位为10000001，减去固定值127之后，得到的结果为-126。
接下来，我们将尾数位转换成十进制数。
这可以通过将每个二进制数位乘以2的相应次方来实现。
在上面的例子中，我们的尾数位为00100001000111111011011，将其转换成十进制数的结果为0.265625。
我们将符号位、指数位和尾数位的结果合并起来，得到最终的浮点数表示。
在上面的例子中，我们的符号位为0，指数位为-126，尾数位为0.265625，所以最终的浮点数为0.265625 * 2^-126。
c语言 小数转这符串
c语言小数转这符串小数转字符串的实现方法在C语言中，将小数转换为字符串是一项常见的操作。
虽然C语言本身没有提供直接的函数来实现这个功能，但是我们可以借助一些库函数或者自己编写代码来实现。
一种常见的方法是使用sprintf函数。
该函数可以将格式化的数据写入字符串中，我们可以利用这个特性将小数转换为字符串。
以下是一个示例代码：```c#include <stdio.h>void floatToString(float num, char* str) {sprintf(str, "%.2f", num);}int main() {float num = 3.14;char str[20];floatToString(num, str);printf("转换后的字符串为：%s\n", str);return 0;}```在上面的代码中，我们定义了一个floatToString函数，该函数接受一个浮点数和一个字符串指针作为参数。
然后利用sprintf函数将浮点数转换为字符串，并将结果存储在str中。
接着在主函数中，我们声明了一个浮点数num，并初始化为3.14。
然后声明了一个足够大的字符数组str，用于存储转换后的字符串。
最后调用floatToString函数将浮点数转换为字符串，并通过printf 函数输出结果。
除了sprintf函数之外，我们还可以使用其他一些方法来实现小数转换为字符串的功能。
例如，我们可以通过自己编写代码来实现这个功能。
以下是一个示例代码：```c#include <stdio.h>void floatToString(float num, char* str) {int integerPart = (int)num;float decimalPart = num - integerPart;sprintf(str, "%d.%02d", integerPart, (int)(decimalPart * 100)); }int main() {float num = 3.14;char str[20];floatToString(num, str);printf("转换后的字符串为：%s\n", str);return 0;}```在上面的代码中，我们首先将浮点数的整数部分和小数部分分别提取出来。