如何將js重寫為java，（使用實例，替換重載）？

Question

假設我們在js中有這樣的function

this.add = function (x, y) {
        if (x instanceof Vector2d) {
            this.x += x.x;   
            this.y += x.y;
            return this;
        }
        this.x += x;
        this.y += y;
        return this;
    };

我是否必須在 java 中重載它，就像：

    public Vector2D add(Vector2D other) {
        this.x += other.x;
        this.y += other.y;
        return new Vector2D(this.x, this.y);
    }
    public Vector2D add(double number) {
        this.x += number;
        this.y += number;
        return new Vector2D(this.x, this.y);
    }

或者有沒有更好/更智能/緊湊的方法來做這些事情？

Answer 1

public class Vector2D {
    private double x;
    private double y;

    //...

    public Vector2D add(Vector2D other) {
        this.x += other.x;
        this.y += other.y;
        return this;
    }
    public Vector2D add(double x, double y) {
        this.x += x;
        this.y += y;
        return this;
    }

    //...
}

您可以在每次調用該方法時返回this而不是創建一個新的Vector2D object，就像您在 js 版本中所做的那樣。

但我覺得這類問題更適合代碼審查社區： https://codereview.stackexchange.com