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php 多态实现

2026-01-29 13:08:40PHP

多态的基本概念

多态是面向对象编程的三大特性之一，允许不同类的对象对同一消息做出响应。在PHP中，多态主要通过继承和接口实现。

通过继承实现多态

父类定义方法，子类重写该方法以实现不同的行为。

php 多态实现

class Animal {
    public function makeSound() {
        echo "Animal sound";
    }
}

class Dog extends Animal {
    public function makeSound() {
        echo "Bark";
    }
}

class Cat extends Animal {
    public function makeSound() {
        echo "Meow";
    }
}

$animals = [new Dog(), new Cat()];
foreach ($animals as $animal) {
    $animal->makeSound();
}

通过接口实现多态

接口定义方法签名，不同类实现接口并提供具体实现。

interface Shape {
    public function calculateArea();
}

class Circle implements Shape {
    private $radius;

    public function __construct($radius) {
        $this->radius = $radius;
    }

    public function calculateArea() {
        return pi() * $this->radius * $this->radius;
    }
}

class Square implements Shape {
    private $side;

    public function __construct($side) {
        $this->side = $side;
    }

    public function calculateArea() {
        return $this->side * $this->side;
    }
}

$shapes = [new Circle(5), new Square(4)];
foreach ($shapes as $shape) {
    echo $shape->calculateArea();
}

抽象类实现多态

抽象类可以包含抽象方法和具体方法，子类必须实现抽象方法。

php 多态实现

abstract class Vehicle {
    abstract public function move();

    public function startEngine() {
        echo "Engine started";
    }
}

class Car extends Vehicle {
    public function move() {
        echo "Car is moving";
    }
}

class Bike extends Vehicle {
    public function move() {
        echo "Bike is moving";
    }
}

$vehicles = [new Car(), new Bike()];
foreach ($vehicles as $vehicle) {
    $vehicle->move();
}

类型提示与多态

在函数参数中使用类型提示，可以接受实现特定接口或继承特定类的对象。

function makeSound(Animal $animal) {
    $animal->makeSound();
}

makeSound(new Dog());
makeSound(new Cat());

魔术方法实现多态

通过魔术方法如__call实现动态方法调用，增加灵活性。

class Polymorphic {
    public function __call($name, $arguments) {
        if ($name == 'execute') {
            echo "Executing with arguments: " . implode(', ', $arguments);
        }
    }
}

$poly = new Polymorphic();
$poly->execute('arg1', 'arg2');