在Java中如何实现多态传递参数_OOP多态参数传递方法分享

class Animal {
    void makeSound() {
        System.out.println("Animal makes a sound");
    }
}
<p>class Dog extends Animal {
@Override
void makeSound() {
System.out.println("Dog barks");
}
}</p><p>class Cat extends Animal {
@Override
void makeSound() {
System.out.println("Cat meows");
}
}</p><p>public class Test {
// 接收Animal类型参数，支持任意子类
static void performSound(Animal animal) {
animal.makeSound();  // 调用实际对象的重写方法
}</p><pre class='brush:java;toolbar:false;'>public static void main(String[] args) {
    Dog dog = new Dog();
    Cat cat = new Cat();

    performSound(dog);  // 输出：Dog barks
    performSound(cat);  // 输出：Cat meows
}

interface Drawable {
    void draw();
}
<p>class Circle implements Drawable {
public void draw() {
System.out.println("Drawing a circle");
}
}</p><p>class Rectangle implements Drawable {
public void draw() {
System.out.println("Drawing a rectangle");
}
}</p><p>public class DrawTest {
// 方法参数为接口类型
static void render(Drawable d) {
d.draw();
}</p><pre class='brush:java;toolbar:false;'>public static void main(String[] args) {
    render(new Circle());     // 输出：Drawing a circle
    render(new Rectangle());  // 输出：Drawing a rectangle
}

interface Shape {
    double area();
}
<p>class Square implements Shape {
private double side;
public Square(double side) { this.side = side; }
public double area() { return side * side; }
}</p><p>class Circle implements Shape {
private double radius;
public Circle(double radius) { this.radius = radius; }
public double area() { return Math.PI <em> radius </em> radius; }
}</p><p>class Calculator {
static void printArea(Shape shape) {
System.out.println("Area: " + shape.area());
}
}</p><p>// 调用
Calculator.printArea(new Square(4));   // 输出：Area: 16.0
Calculator.printArea(new Circle(3));   // 输出：Area: 28.27...</p>