day08 do while 循环_for循环语句_嵌套循环

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do while 循环

//do while 循环
public class DowhileDemo
{
    public static void main(String[] args) 
    {
        /*
            do
            {
                循环体语句
            }
            while(boolean表达式);
        */
        //叫500次帅哥
        int sum = 0;
        do
        {
            //System.out.println("帅哥"+sum);
            sum++;
        }
        while (sum <= 500);
        //从1数到100,打印1-100
        int count = 0;
        do
        {
            //System.out.println(count);
            count++;
        }
        while (count <= 100);
        //计算100以内的正整数的和
        int number = 1;
        int result = 0;//最终的和
        do
        {
            result = result + number;
            number++;
        }
        while (result <= 100);//判断为false,会执行一次,但是不会循环.
        System.out.println(result);
    }
}

for循环

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public class ForDemo 
{
    public static void main(String[] args) 
    {
        /*
            for( 初始化语句; boolean表达式;循环后操作语句 )
            {
                循环体语句
            }
            执行顺序:
                1:初始化语句
                2:boolean表达式:
                        为true:进入第3步
                        为false:跳过循环
                3:执行循环体语句
                4:执行循环后操作语句
                5:进入第2步
            注意:初始化语句只在最开始的时候执行一次,一般定义一个变量,并赋值
        */
        
        for ( int count = 0; count < 5;count++)
        {
            //System.out.println("帅哥"+count);
        }
        for (int num = 1;num <= 100 ;num ++ )
        {
            //System.out.println(num);
        }
        //计算100以内的正整数和
        int result = 0;
        for (int number = 1;number <= 100 ;number++ )
        {
            result =result+number;
        }
        System.out.println(result);
    }
}

嵌套循环

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//嵌套查询
public class LoopInloopDemo 
{
    public static void main(String[] args) 
    {
        //需求:重复打印四次1-100的数字
        for (int j = 1; j <= 4;j++ )
        {
            for (int i = 0;i < 100 ;i ++ )
            {
                System.out.println("帅哥"+i);
            }
        }
        
        
    }
}