Examples of constructor methods in php object-oriented programming

Let me introduce to you an example of the construction method of PHP object-oriented programming. Friends in need can refer to it.

Basic syntax for customizing constructors in classes: //php5 [Modifier]function __construct([parameter list]){ } //php4 [Modifier]function class name([parameter list]){ }

Learn programming, novices learn PHP object-oriented programming, look at more examples and practice more, and you will make rapid progress. No matter how good the PHP tutorial is, it can't teach you how to write code. You can only practice more on your own!

Let’s look at specific examples so that it’s easier to understand.

<?php
/**
  php 构造方法
  * by 程序员之家 bbs.it-home.org
*/
    class Person{
    
        public $name;
        public $age;

        //构造方法 php5 
        public function __construct($name,$age){
            
            $this->name=$name;
            $this->age=$age;
        }

        //构造方法 php4   写在这里是php5为了兼容PHP4
        public function Person($name,$age){
            
            $this->name=$name;
            $this->age=$age;
        }        
    }

    $p1=new Person("老大",27);
    echo $p1->name;
    $p1=new Person("小二",26);
    $p1=new Person("小三",24);
?>

Note: 1), understanding of $this: 1. The essence of $this can be understood to be the address of this object. 2. Which object uses $this is the address of that object. 3. $this cannot be used outside the class 2) Understanding of construction methods: The constructor method name is the same as the class name (php4 version). The constructor method name of php5 version can be the same as the class name, or it can be __construct(). The default access modifier of the constructor is public, and the constructor has no return value. After successfully creating a new object, the system automatically calls the constructor of the class. A class has one and only one constructor. After PHP5, although __construct() and classname() can coexist, only one can actually be used. If there is no custom constructor for the class, the class uses the system default constructor. If a constructor is customized for a class, the default constructor of the class is overridden.

With the above learning, PHP object-oriented constructor is no longer difficult.