利用兩個變量實現兩個數交換值

/**

*兩個變量

*/

public class Test{
    public static void main(String[] args){
        Scanner in =new Scanner(System.in);
        int a=0,b=0;
        System.out.print("請輸入第1個數：");
        a = in.nextInt();
        System.out.print("請輸入第2個數：");
        b = in.nextInt();
        System.out.println("交換前:"+a+","+b);
        a=a+b;
        b=a-b;
        a=a-b;
        System.out.println("交換前:"+a+","+b);
    }    
}

/** *三個變量 */ 

public class Test05{  
    public static void main(String[] args){ //實現兩數交換，輸出交換前後的結果  
        int a=10,b=20;  
        int t;//t表示空杯  
        System.out.println("交換前：a="+a+",b="+b);  
        t=a;  
        a=b;  
        b=t;  
        System.out.println("交換後：a="+a+",b="+b+"");  
    } 
}