明解JAVA第三章答案

明解JAVA第三章答案练习3-1
package candle1220;
import java.util.Scanner;
public class Nightwatch {
public static void main(String[] args){
Scanner stdIn=new Scanner(System.in);
System.out.print("整数值");
int n=stdIn.nextInt();
if(n>0)
System.out.println("其绝对值是"+(n));
else
System.out.println("其绝对值是"+(-n));
}
}
练习3-2
package candle1220;
import java.util.Scanner;
public class Nightwatch {
public static void main(String[] args){
Scanner stdIn=new Scanner(System.in);
System.out.print("整数A：");
int a=stdIn.nextInt();
System.out.print("整数B：");
int b=stdIn.nextInt();
if(a%b==0)
System.out.println(b+"是"+a+"的约数");
else
System.out.println(b+"不是"+a+"的约数");
}
}
练习3-3
同样可以运⾏
练习3-4
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in);
System.out.print("a:");
int a=input.nextInt();
System.out.print("b:");
int b=input.nextInt();
if(a>b)
System.out.print("a更⼤");
else
if(a==b)
System.out.print("⼀样⼤");
else
System.out.print("b更⼤");
}
}
练习3-5
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in);
System.out.print("请输⼊⼀个正整数:");
int a=input.nextInt();
if(a<=0)
System.out.print("请输⼊正整数");
else if(a%5==0)
System.out.print("该值可以被5整除");
else
System.out.print("该值不可以被5整除"); }
}
练习3-6
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in);
System.out.print("请输⼊⼀个正整数:");
int a=input.nextInt();
if(a<=0)
System.out.print("请输⼊正整数");
else if(a%10==0)
System.out.print("该值是10的倍数");
else
System.out.print("该值不是10的倍数"); }
}
练习3-7
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in);
System.out.print("请输⼊⼀个正整数:");
int a=input.nextInt();
if(a<=0)
System.out.print("请输⼊正整数");
else if(a%3==0)
System.out.print("该值可以被3整除");
else if(a%3==1)
System.out.print("该值除以3余1");
else
System.out.print("该值除以3余2");
}
}
练习3-8
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in);
System.out.print("请输⼊分数:");
int a=input.nextInt();
if(a>=0&&a<60)
{System.out.println("不及格");}
else if(a>=60&&a<70)
{System.out.println("及格");}
else if(a>=70&&a<80)
{System.out.println("良");}
else if(a>=80&&a<=100)
{System.out.println("优");}
else
{System.out.println("请输⼊合理的分数");} }
}
练习3-9
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in); System.out.print("a=:");
int a=input.nextInt();
System.out.print("b=:");
int b=input.nextInt();
System.out.print(a>b?a:b);
}
}
练习3-10
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input =new Scanner (System.in); System.out.print("a=");
int a=input.nextInt();
System.out.print("b=");
int b=input.nextInt();
if(a>=b)
System.out.print(a-b);
else
System.out.print(b-a);
}
}
练习3-11
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input =new Scanner (System.in); System.out.print("a=");
int a=input.nextInt();
System.out.print("b=");
int b=input.nextInt();
int c=a-b;
if(c>10||c<-10)
System.out.print("它们的差值⼤于等于11");
else
System.out.print("它们的差值⼩于等于10"); }
}
练习3-12
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner(System.in); System.out.print("a=");
int a =input.nextInt();
System.out.print("b=");
int b =input.nextInt();
System.out.print("c=");
int c =input.nextInt();
int min1=a<b?a:b;
int min=min1<c?min1:c;
System.out.print(min);
}
}
练习3-13
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner (System.in); System.out.print("a=");
int a =input.nextInt();
System.out.print("b=");
int b =input.nextInt();
System.out.print("c=");
int c =input.nextInt();
int mid1=a<b?b:a;
int mid=mid1<c?mid1:c;
System.out.print(mid);
}
}
练习3-14
// 计算两个整数值中较⼩的值和较⼤的值import java.util.Scanner;
class New {
public static void main(String[] args) {
Scanner stdIn = new Scanner(System.in); System.out.print("整数a：");
int a = stdIn.nextInt();
System.out.print("整数b：");
int b = stdIn.nextInt();
if(a==b){
System.out.print("两个整数相等");
}
else{
int min, max; // 较⼩的值／较⼤的值
if (a < b) { // 如果a⼩于b
min = a;
max = b;
}
else
{ // 否则
min = b;
max = a;
}
System.out.println("较⼩的值是" + min + "。

"); System.out.println("较⼤的值是" + max + "。

"); }
}
}
练习3-15
// 计算两个整数值中较⼩的值和较⼤的值
import java.util.Scanner;
class New {
public static void main(String[] args) {
Scanner stdIn = new Scanner(System.in);
System.out.print("整数a：");
int a = stdIn.nextInt();
System.out.print("整数b：");
int b = stdIn.nextInt();
if(a==b){
System.out.print("两个整数相等");
}
else{
int min, max; // 较⼩的值／较⼤的值
if (a < b) { // 如果a⼩于b
min = a;
max = b;
}
else
{ // 否则
min = b;
max = a;
}
System.out.print(max+" ");
System.out.println(min);
}
}
}
练习3-16
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner(System.in);
System.out.print("a=");
int a =input.nextInt();
System.out.print("b=");
int b =input.nextInt();
System.out.print("c=");
int c =input.nextInt();
int min1=a<b?a:b;
int min=min1<c?min1:c;
int mid1=a<b?a:b;
int mid=mid1>c?mid1:c;
int max1=a>b?a:b;
int max=max1>c?max1:c;
System.out.print(min+" ");
System.out.print(mid+" ");
System.out.print(max);
}
}
练习3-17
import java.util.Scanner;
import java.util.Random;
public class New{
public static void main(String[] args){
Scanner input=new Scanner(System.in); Random rand=new Random();
int a=rand.nextInt(3);
switch(a){
case 0:System.out.println("⽯头");break;
case 1:System.out.println("剪⼑");break;
case 2:System.out.println("布"); break; }
}
}
练习3-18
import java.util.Scanner;
public class New{
public static void main(String[] args){
Scanner input=new Scanner(System.in); System.out.print("输⼊⽉份:");
int mouth=input.nextInt();
switch(mouth){
case 1:
case 2:
case 3:System.out.println("春");break;
case 4:
case 5:
case 6:System.out.println("夏");break;
case 7:
case 8:
case 9:System.out.println("秋");break;
case 10:
case 11:
case 12:System.out.println("冬");break; }
}
}。