初学JAVA 10道入门小程序

1、编写程序实现对给定的 4 个整数从大到小的顺序排列。

package com.cn;

import java.util.Scanner;

public class JavaDemo01 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int a,b,c,d,t;
		System.out.printf("请输入四个整数");
		Scanner in=new Scanner(System.in);
		a=in.nextInt();
		b=in.nextInt();
		c=in.nextInt();
		d=in.nextInt();
		if(a <b){ t = a; a = b; b = t;}
	    if(b <c){ t = c; c= b; b = t;}
	    if(c <d){ t = d; d = c; c = t;}
	    if(a <b){ t = a; a = b; b = t;}
	    if(b <c){ t = c; c= b; b = t;}
	    if(c <d){ t = c; c= d; d = t;}
	    System.out.println(a+"\t"+b+"\t"+c+"\t"+d);
	}

}

2、输入 3 个正整数（边长），判断能否构成一个三角形。

package com.cn;
import java.util.Scanner;
public class JavaDeme02 {
	public static void main(String[] args) {
		// TODO Auto-generated method stub