使用来自另一个类的变量实现构造函数

Question

我是一个java初学者，想要一些帮助实现我的构造函数

例如

public Class WidthLenth {
private double width;
private double length;
public WidthLength(double width, double length) {
this.width = width;
this.length = length;
}
public double getWidth() {
return width;
}
public double getLength() {
return length;
}

和另一个类

public Class Rectangle {
private WidthLength widthLength <-- there is a uni-directional relationship here
private String color

我需要构造函数是这样的格式

public Rectangle(double width, double length, String color) {
}

所以方法

public getWidthLenth() {
}

。

如何实现这个构造函数?

Answer 1

您只需在构造函数中创建一个新的WidthLength对象。

public Rectangle(double width, double length, String col)
{
    widthLength = new WidthLength(width, length);
    color = col;
}

Answer 2

try this:

public Rectangle(double width, double length, String color) {
    this.widthLength = new WidthLength(width, length);
    this.color = color;
}
public WidthLength getWidthLength() {
    return this.widthLength;
}