课程进度 29% · 第7/22章第7/22章 · 标签 1/3
— 1 —
类与对象
```php
<?php
class User {
public $name;
private $email;
protected $role;
public function __construct($name) { $this->name = $name; }
public function greet() { return "Hello, {$this->name}!"; }
}
$user = new User("Tom");
echo $user->greet();
?>
```
php
1
2
class User {
3
public $name;
4
private $email;
5
protected $role;
6
public function __construct($name) { $this->name = $name; }
7
public function greet() { return "Hello, {$this->name}!"; }
8
}
9
$user = new User("Tom");
10
echo $user->greet();
11
— 2 —
继承与多态
```php
<?php
class Animal { public function speak() { return "..."; } }
class Dog extends Animal { public function speak() { return "汪汪"; } }
class Cat extends Animal { public function speak() { return "喵喵"; } }
function makeSound(Animal $a) { echo $a->speak(); }
makeSound(new Dog()); makeSound(new Cat());
?>
```
php
1
2
class Animal { public function speak() { return "..."; } }
3
class Dog extends Animal { public function speak() { return "汪汪"; } }
4
class Cat extends Animal { public function speak() { return "喵喵"; } }
5
function makeSound(Animal $a) { echo $a->speak(); }
6
makeSound(new Dog()); makeSound(new Cat());
7
class继承多态publicprivate