What is the way to instantiate a class in php

php method to instantiate a class: first declare a class, you can add some keywords before class, such as abstract or final; then the format of the instantiated object is [$ variable name = new class name (); 】.

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php method of instantiating a class:

The instantiation of a class is an object. A class can be divided into two parts. One is the static description, which is the member attributes in the class. The second is dynamic description, which is the member method in the class, which is the function of the object.

To declare a class, you can add some keywords before class, such as abstract or final, etc.

When declaring a variable in a class, add a keyword in front of it, usually var, as well as public, private, static, and other keywords.

• public //Set member properties to public permissions

• private //Set member properties to private permissions

• static //Set the member properties to static permissions

The format of the instantiated object is

$变量名 = new 类名();   //括号里可传参数

The format of assigning values ​​to the member properties in the object The format for calling member methods in an object for

$引用名 ->成员属性 = 值;

is

$引用名 -> 成员方法;

The format for using member properties for member methods is

$this -> member properties;

<?php
    class Person{
        var $name;
        var $age;
        var $sex;
         
        function walk(){
            echo $this ->name." is walking.";
        }
    }
     
    $Boy = new Person();
    $Boy ->name = "John";
    $Boy -> walk();
?>

Execution result

If the member method directly uses the member attribute, you cannot use

to change the above code

function walk(){
    echo $name." is walking.";
}

Execution result

The member method was not called successfully. The member attribute

$this reference represents the class. In the above code, in the Person class, $this It represents the Person object. $this can not only reference members but also member methods. The usage is the same.

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