PHP类如何定义_PHP类的定义语法与基本结构说明

class ClassName {
    // 属性
    public $property;

    // 方法
    public function methodName() {
        // 方法体
    }
}

class User {
    public $name;
    public $email;

    public function sayHello() {
        return "Hello, I'm " . $this->name;
    }
}
</font>

<H3>类的访问修饰符</H3>
<p>PHP支持三种访问控制修饰符，用于限制属性和方法的访问范围：</p><p><span>立即学习</span>“<a href="https://pan.quark.cn/s/7fc7563c4182" style="text-decoration: underline !important; color: blue; font-weight: bolder;" rel="nofollow" target="_blank">PHP免费学习笔记（深入）</a>”；</p>
<ul>
  <li><strong>public</strong>：可在任何地方访问</li>
  <li><strong>protected</strong>：只能在类本身及其子类中访问</li>
  <li><strong>private</strong>：仅在定义它的类内部可访问</li>
</ul>
<p>建议根据实际需求设置合适的修饰符，以增强封装性。</p>
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<H3>构造函数与析构函数</H3>
<p>类中常用<strong>__construct()</strong>作为构造方法，在创建对象时自动执行，常用于初始化属性。</p>
<font face="Courier New">
<pre class="brush:php;toolbar:false;">
class User {
    public $name;

    public function __construct($name) {
        $this->name = $name;
    }
}
$user = new User("Alice");

$user = new User("Bob");
echo $user->sayHello(); // 输出: Hello, I'm Bob
</user>