helloworld.java

一些java程序

package exercise_java;

import java.util.Scanner;

public class HelloWorld {
	public static void main(String[] args) throws Exception{
		
		Scanner in = new Scanner(System.in);
		
		System.out.println("Hello world");
		
		System.out.println("100,1000,10000");
		System.out.println("please select a number above " +
				"which you want to print the \"Hello world\"");
		
		int times=in.nextInt();
		
		System.out.println("if you want to kown the number of each \" hello world \",choose 1(for yes) or 0(not).");
		int n=in.nextInt();
		
		
		switch(n){
		case 0:
		for(int i=1;i<times+1;i++){
			System.out.print("Hello world"+"  ");
			if(i%5==0) System.out.println("");
			}
		break;
		
		
		
//		for(int i=1;i<times+1;i++){
//			System.out.print("Hello world"+"  ");
//			if(i%5==0) System.out.println("");
//			}
//		System.out.println("");
//		
//		
//		
//		for(int i=1;i<10001;i++){
//			System.out.print("Hello world"+"  ");
//			if(i%5==0) System.out.println("");
//			}
//		System.out.println("");

		case 1:
		for(int i=1;i<times+1;i++){
			System.out.print(i+":"+"Hello world"+" ");
			if(i%5==0) System.out.println("");
		}
		break;
		}
		
		System.out.println();
		System.out.println();
		System.out.println();
		System.out.println("i will print a number every five times.");
		int k=1;
		do{
			System.out.print(k+":");
			for(int i=1;i<=5;i++)
			{
				System.out.print("Hello world");
			}
			System.out.println();
			k++;
		}while(k<21);
		
	}

}