循环的嵌套

常见的是两层嵌套

for for

for while

while while

while for

/*
循环的嵌套:
*/
public class NestDemo1{
    public static void main(String[] args){

for(int i =1; i<=5;i++){//外层循环
            //System.out.println();
            for(int j =0;j<3;j++){//内层循环
                System.out.println("hello");
            }
            System.out.println("---------")
        }
    }
}

/*
 用嵌套打印等腰三角形
*/
public class ForForDemo1{
	public static void main(String[] args){
		//for(int i =0;i<10;i++){
			int i = 0;
			while (i<10){
				for(int j =0;j<10-i;j++){
				System.out.print("$");
			}
			i++;
			System.out.println();
			}
		//}	
		
	}
}


/*public class ForForDemo1{
	public static void main(Stirng[] args){
		for(int i = 0;i<=10;i++){
			for(int j=0;j<11-i;j++){
				System.out.print("s");
			}System.out.println();
		}
	}
}
*/

　　

/*
从键盘上输入一个数,和随机数比较,并给出大小提示
*/
/*
 import java.util.Scanner;
 public class GuessNumber{
     public static void main (String[] args){
         Scanner s =new Scanner(System.in);
         int r = (int)(Math.random()*100 + 1);
         for(;;){
             System.out.print("输入一个数:(1-100)");
             int n = s.nextInt();
             if(n==r){
                 System.out.println("猜中了");
                 break;
             }else if(n<r){
                 System.out.println("小了");
             }else if(n>r){
                 System.out.println("大了");
             }
         }
     }
 }
 */
 
 //import java.util.Scanner;
 public class GuessNumber{
     public static void main (String[] args){
         //Scanner s =new Scanner(System.in);
         int r = (int)(Math.random()*(88-55+1) + 33);
         for(;;){
             //System.out.print("输入一个数:(33-88)");
            // int n = s.nextInt();
            int n = (int)(Math.random()*(88-55+1)+33);
            System.out.print(n);
             if(n==r){
                 System.out.println("猜中了");
                 //break;
                 continue;
             }else if(n<r){
                 System.out.println("小了");
             }else if(n>r){
                 System.out.println("大了");
             }
         }
     }
 }