java 排序问题怎么解决？？？？？？？？？？？

Question

int y=10;
int z=30;
z=z+y;
y=z-y;
z=z-y;
System.out.println(z);
System.out.println(y);
为什么y和z会交换为什么

Answer 1

int y = 10;
    int z = 30;

    int temp = z + y;//把和用temp接收
    y = temp - y;//实际上就是z+y-y
    z = temp - z;//实际上就是z+y-z
    System.out.println(y);
    System.out.println(z);