Java：访问器方法？ 增变方法？

Question

Consider a potential instance method named rotate that would rotate a Rectangle object 90 degrees by swapping its width and height values. For example, if a Rectangle's dimensions are 10 x 30, then calling the rotate method would change its dimensions to 30 x 10.

I think this will be an accessor method, right? Since we are not actually changing the values?

Answer 1

Accessor Methods

An accessor method is used to return the value of a private field.

Mutator Methods

A mutator method is used to set a value of a private field.

So here as you are changing the state of private fields so it is a mutator.

Answer 2

See this discussion of the meaning of accessor methods. The general opinion is that they do not modify state. If you are rotating the object, you are modifying its state and rotate is mutating the object.

Answer 3

Any method that changes an object's state is properly a mutator. As you are changing the dimensions (through the swap) it is a mutation. These would be accessor methods given your class definition,

public int getX() { return x; }
public int getY() { return y; }
public int getWidth() { return width; }
public int getHeight() { return height; }