C++-函数重载（reload）,函数定义声明（voidfunc（int））

C++-函数重载（reload）,函数定义声明（voidfunc（int））对于相同的函数名字，根据其输⼊的变量不同进⾏函数重载
/*
根据函数的输⼊变量不同进⾏函数重载
*/
#include <iostream>
using namespace std;
void foo(int i) {
cout << "int foo(int i)" << endl;
}
void foo(int i, int j) {
cout << "void foo(int i, int j)" << endl;
}
void foo(int i, double j) {
cout << "void foo(int i, double j)" << endl;
}
int main(void) {
int a = 0;
double b = 0;
foo(a, b);
return0;
}
对于函数重载，如果char->int 表⽰向上采样, short -> char 表⽰向下采样
/*
变量不匹配进⾏重载
*/
#include <iostream>
using namespace std;
void func(int i) { // char - > int
cout << "func(1)" << endl;
}
void func(const char i) { // char - > const char
cout << "func(2)" << endl;
}
//sort->char 降级匹配
void foo(char i) {
cout << "foo(1)" << endl;
}
//sort->int 升级匹配
void foo(int i) {
cout << "foo(2)" << endl;
}
//省略匹配
void hum(int i, ...) {
cout << "hum(1)" << endl;
}
//double->int 降级匹配
void hum(int i, int j) {
cout << "hum(2)" << endl;
}
int main() {
char c = 2;
func(c);
short s = 2;
foo(s);
int i = 0;
double j = 0;
hum(i, j);
}
在开头进⾏函数声明，同时定义变量，使得未输⼊的函数有初始值/*
进⾏函数声明和变量预定义
*/
#include <iostream>
using namespace std;
//函数预声明
void func(int a = 10, int b = 10, int c = 20);
int main(void) {
func(11, 20, 30);
func(11, 20);
func(11);
}
void func(int a, int b, int c) {
cout << a << "," << b << "," << c << endl;
}。