Java中while和do-while

while (表达式) {
    循环体;
}

public class Test {
    public static void main(String[] args) {
        int  i = 0;
        int  sum = 0;
        // 1+2+3+…+100=?
        while (i <= 100) {
            sum += i;//相当于sum = sum+i;
            i++;
        }
        System.out.println("Sum= " + sum);
    }
}

do {
        循环体;
     } while(表达式) ;

public class Test {
    public static void main(String[] args) {
        //while循环：先判断再执行
        int a = 0;
        while (a < 0) {
            System.out.println(a);
            a++;
        }
        System.out.println("-----");
        //do-while循环：先执行再判断
        a = 0;
        do {
            System.out.println(a);
            a++;
        } while (a < 0);
    }
}