n++和++n相關基礎知識梳理

 

 

public class Demo {
    public static void main(String[] args) {
        int a = 5;
        int b = 5;
        int m = 5;
        int n = 5;
        int x = 5;
        int y = 5;
        for (int i = 0; i < 5; i++) {
            a++;       // 等同於： a = a + 1
            System.out.print(i + "  a:" + a);
            ++b;       // 等同於： b = b + 1
            System.out.print(", b:" + b);
            m = ++m;   // 先自增後賦值，等同於： m = m + 1
            System.out.print(", m:" + m);
            n = n++;   // 先賦值後自增，等同於： n = n
            System.out.print(", n:" + n);
            x += x++;  // 等同於： x = x + x
            System.out.print(", x:" + x);
            y += ++y;  // 等同於： y = y + y + 1
            System.out.print(", y:" + y);
            System.out.println();
        }
        System.out.println("a=" + a + ", b=" + b + ", m=" + m +", n=" + n +",x=" + x + ",y=" + y);
    }
}

結果： 

0  a:6, b:6, m:6, n:5, x:10, y:11
1  a:7, b:7, m:7, n:5, x:20, y:23
2  a:8, b:8, m:8, n:5, x:40, y:47
3  a:9, b:9, m:9, n:5, x:80, y:95
4  a:10, b:10, m:10, n:5, x:160, y:191
a=10, b=10, m=10, n=5,x=160,y=191