原文： https://beginnersbook.com/2017/09/java-program-to-find-area-of-geometric-figures-using-method-overloading/

该程序使用方法重载找到正方形，矩形和圆形的面积。在这个程序中，我们有三个同名的方法area()，这意味着我们正在重载area()方法。通过面积方法的三种不同实现，我们计算方形，矩形和圆形的面积。

要理解这个程序，你应该具备以下核心 Java 主题的知识：
Java 中的方法重载

示例：使用方法重载编程以查找方形，矩形和圆的面积

  1. class JavaExample
  2. {
  3.     void calculateArea(float x)
  4.     {
  5.         System.out.println("Area of the square: "+x*x+" sq units");
  6.     }
  7.     void calculateArea(float x, float y)
  8.     {
  9.         System.out.println("Area of the rectangle: "+x*y+" sq units");
  10.     }
  11.     void calculateArea(double r)
  12.     {
  13.         double area = 3.14*r*r;
  14.         System.out.println("Area of the circle: "+area+" sq units");
  15.     }
  16.     public static void main(String args[]){
  17.         JavaExample obj = new JavaExample();
  19.         /* This statement will call the first area() method
  20.          * because we are passing only one argument with
  21.          * the "f" suffix. f is used to denote the float numbers
  22.          * 
  23.          */
  24.      obj.calculateArea(6.1f);
  26.      /* This will call the second method because we are passing 
  27.       * two arguments and only second method has two arguments
  28.       */
  29.      obj.calculateArea(10,22);
  31.      /* This will call the second method because we have not suffixed
  32.       * the value with "f" when we do not suffix a float value with f 
  33.       * then it is considered as type double.
  34.       */
  35.      obj.calculateArea(6.1);
  36.     }
  37. }

输出：

  1. Area of the square: 37.21 sq units
  2. Area of the rectangle: 220.0 sq units
  3. Area of the circle: 116.8394 sq units