关于方法传参问题，形参和实参

Question

java问题

public class Test {
    public static void main(String[] args) {
        StringBuffer a = new StringBuffer("A");//001->x
        StringBuffer b = new StringBuffer("B");//002->y->001
        operator(a,b);
        System.out.println(a+","+b);
    }
    public static void operator(StringBuffer x, StringBuffer y) {
        x.append(y);
        y = x;
    }
}

为啥最后输出结果为AB，B，而不是AB，AB

Answer 1

记住一句话就可以了：Java中只有值传递。