public void moveCircle(Circle circle, int deltaX, int deltaY) { // code to move origin of circle to x+deltaX, y+deltaY circle.setX(circle.getX() + deltaX); circle.setY(circle.getY() + deltaY); // code to assign a new reference to circle circle = new Circle(0, 0); }
https://docs.oracle.com/javase/tutorial/java/javaOO/arguments.html
方法内部不能通过修改引用的值来改变这个引用对象；
Passing Reference Data Type Arguments
原文：https://www.cnblogs.com/lishidefengchen/p/10981171.html