while和do while循环

while和do while循环

package Basic;

public class Test2 {
    public static void main(String[] args) {
        while (true){//while死循环
            System.out.println("浩哥牛X");
        }
    }
}

package Basic;

public class Test2 {
    public static void main(String[] args) {
        int i = 0;
        while (i < 5){
            System.out.println("浩哥牛X");
            i++;
        }
    }
}

浩哥牛X
浩哥牛X
浩哥牛X
浩哥牛X
浩哥牛X

Process finished with exit code 0

package Basic;
import java.util.Scanner;

public class Test2 {
    public static void main(String[] args) {//运用死循环实现监听输入，符合条件返回相应值或退出。
        Scanner scanner = new Scanner(System.in);
        int i = 0;
        flag:while (i != 5){
            System.out.println("请输入一个数字：");
            i = scanner.nextInt();
            if(i>8){
                System.out.println("浩哥牛X");
            }else if (i==5){//break 返回 flag
                break flag;
            }else {
                System.out.println("输错了！快重新输入！");
            }



        }
        System.out.println("程序正常退出！");
    }
}
请输入一个数字：
4
输错了！快重新输入！
请输入一个数字：
9
浩哥牛X
请输入一个数字：
5
程序正常退出！
Process finished with exit code 0

package Basic;
import java.util.Scanner;

public class Test2 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入一个数字：");
        int i = scanner.nextInt();

        while (i > 5) {//while是先判断满足条件后执行，当不满足条件时不在执行
            System.out.println("while：");
            i--;
        }
        System.out.println("============================================");

        do {//do while是先执行再判断，满足条件再继续执行。不满足条件不再执行，这时结果执行了一次。
            System.out.println("do while:");
        }while (i>10);

            }

        }

请输入一个数字：
6
while：
============================================
do while:

Process finished with exit code 0