While循环

循环结构

1. while 循环

2. do...while 循环

3. for循环

   在Java5中引入了一种主要用于数组的增强型for循环

while 循环

package com.chen.cm.struct;

public class WhileDemo03 {
    public static void main(String[] args) {

        //计算1+2+3+...+100=?
        //高斯的故事

        int i=0;
        int sum=0;

        while(i<=100){
            sum=sum+i;
            i++;
        }
        System.out.println(sum);
    }
}

do...while 循环

package com.chen.cm.struct;

public class DoWhileDemo01 {
    public static void main(String[] args) {
        int i=0;
        int sum=0;

        do{
            sum=sum+i;
            i++;
        }while(i<=100);

        System.out.println(sum);
    }
}

体会执行结果区别

package com.chen.cm.struct;

public class DoWhileDemo02 {
    public static void main(String[] args) {
        int a=0;
        while(a<0){
            System.out.println(a);
            a++;
        }
        System.out.println("===================");
        do{
            System.out.println(a);
            a++;
        }while(a<0);
    }
}