class People {
float hello(int a,int b) {
return a+b;
}
float hello(long a,int b) {
return a-b;
}
double hello(double a,int b) {
return a*b;
}
}
public class Example4_12 {
public static void main(String args[]) {
People tom = new People();
System.out.println(tom.hello(10,20));
System.out.println(tom.hello(10L,20));
System.out.println(tom.hello(10.0,20));
}
}

重载的参数也可以是一个对象

Circle.java

public class Circle {
double radius,area;
void setRadius(double r) {
radius=r;
}
double getArea(){
area=3.14*radius*radius;
return area;
}
}

Tixing.java

public class Tixing {
double above,bottom,height;
Tixing(double a,double b,double h) {
above = a;
bottom = b;
height = h;
}
double getArea() {
return (above+bottom)*height/2;
}
}

Student.java

public class Student {
double computerArea(Circle c) {
double area=c.getArea();
return area;
}
double computerArea(Tixing t) {
double area=t.getArea();
return area;
}
}

Example4_13.java

public class Example4_13 {
public static void main(String args[]) {
Circle circle = new Circle();
circle.setRadius(196.87);
Tixing lader = new Tixing(3,21,9);
Student zhang = new Student();
System.out.println("zhang计算圆的面积:");
double result=zhang.computerArea(circle);
System.out.println(result);
System.out.println("zhang计算梯形的面积:");
result=zhang.computerArea(lader);
System.out.println(result);
}
}