[使用 PHP 构造函数初始化类中的对象的属性]
在下面的示例中，我们将创建一个类 Student 并使用 __construct 函数为 new Student 分配其属性。
__construct 函数减少了与使用函数 set_name() 相关的代码数量。
<?php class Student { // Define the attributes of your class public $name; public $email; // Initialize the properties of the object you want to create in this class function __construct($name, $email) { $this->name = $name; $this->email = $email; } function get_name() { return $this->name; } function get_email() { return $this->email; } } $obj = new Student("John", "john567@gmail.com"); echo $obj->get_name(); echo "<br>"; echo $obj->get_email(); ?>
输出：
John john567@gmail.com
[使用 PHP 构造函数在类中初始化 Object with Parameters 的属性]
在下面的示例代码中，我们创建类 Military 并使用 __construct 函数来提供我们创建的对象的属性和参数。
<?php class Military { // Define the attributes of the class 'Military' public $name; public $rank; function __construct($name, $rank){ $this->name = $name; $this->rank = $rank; } function show_detail() { echo $this->name." : "; echo "Your Rank is ".$this->rank."\n"; } } $person_obj = new Military("Michael", "General"); $person_obj->show_detail(); echo "<br>"; $person2 = new Military("Fred", "Commander"); $person2->show_detail(); ?>
输出：
Michael : Your Rank is General Fred : Your Rank is Commander
[在 PHP 中在子类中启动一个对象并在两个类都有 Individual 构造函数时调用父类构造函数]
<?php class Student { public $name; public function __construct($name) { $this->name = $name; } }class Identity extends Student { public $identity_id; public function __construct($name, $identity_id) { parent::__construct($name); $this->identity_id = $identity_id; } function show_detail() { echo $this->name." : "; echo "Your Id Number is ".$this->identity_id."\n"; } } $obj = new Identity('Alice', '1036398'); echo $obj->show_detail(); ?>
输出：
Alice : Your Id Number is 1036398
Identity 类扩展了上述代码中的 Student 类。我们使用关键字 parent: 来调用 Student 类的构造函数。
