Table of Contents
ThinkPHP中__initialize()和类的构造函数__construct()用法分析,thinkphp构造函数
Home php教程 php手册 ThinkPHP中__initialize()和类的构造函数__construct()用法分析,thinkphp构造函数

ThinkPHP中__initialize()和类的构造函数__construct()用法分析,thinkphp构造函数

Jun 13, 2016 am 09:19 AM
thinkphp function Constructor usage

ThinkPHP中__initialize()和类的构造函数__construct()用法分析,thinkphp构造函数

本文实例分析了ThinkPHP中的__initialize()和类的构造函数__construct()。分享给大家供大家参考。具体分析如下:

thinkphp中的__construct是不可以随便用的,因为你的模块类继承上级类,上级类有定义好的;

1、__initialize()不是php类中的函数,php类的构造函数只有__construct().

2、类的初始化:子类如果有自己的构造函数(__construct()),则调用自己的进行初始化,如果没有,则调用父类的构造函数进行自己的初始化。

3、当子类和父类都有__construct()函数的时候,如果要在初始化子类的时候同时调用父类的__constrcut(),则可以在子类中使用parent::__construct().

如果我们写两个类,如下:

复制代码 代码如下:

class Action{ 
    public function __construct() 
    { 
        echo 'hello Action'; 
    } 

class IndexAction extends Action{ 
    public function __construct() 
    { 
        echo 'hello IndexAction'; 
    } 

$test = new IndexAction; 
//output --- hello IndexAction


很明显初始化子类IndexAction的时候会调用自己的构造器,所以输出是'hello IndexAction',但是将子类修改为:

复制代码 代码如下:

class IndexAction extends Action{ 
    public function __initialize() 
    { 
        echo 'hello IndexAction'; 
    } 
}


那么输出的是'hello Action',因为子类IndexAction没有自己的构造器,如果我想在初始化子类的时候,同时调用父类的构造器呢?

复制代码 代码如下:

class IndexAction extends Action{ 
    public function __construct() 
    { 
        parent::__construct(); 
        echo 'hello IndexAction'; 
    } 
}


这样就可以将两句话同时输出,当然还有一种办法就是在父类中调用子类的方法.

复制代码 代码如下:

class Action{ 
    public function __construct() 
    { 
        if(method_exists($this,'hello')) 
        { 
            $this -> hello(); 
        } 
        echo 'hello Action'; 
    } 

class IndexAction extends Action{ 
    public function hello() 
    { 
        echo 'hello IndexAction'; 
    } 
}


这样也可以将两句话同时输出,而这里子类中的方法hello()就类似于ThinkPHP中__initialize()。

所以,ThinkPHP中的__initialize()的出现只是方便程序员在写子类的时候避免频繁的使用parent::__construct(),同时正确的调用框架内父类的构造器,所以,我们在ThnikPHP中初始化子类的时候要用__initialize(),而不用__construct(),当然你也可以通过修改框架将__initialize()函数修改为你喜欢的函数名.

希望本文所述对大家的ThinkPHP框架程序设计有所帮助。

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Tips for dynamically creating new functions in golang functions Tips for dynamically creating new functions in golang functions Apr 25, 2024 pm 02:39 PM

Go language provides two dynamic function creation technologies: closure and reflection. closures allow access to variables within the closure scope, and reflection can create new functions using the FuncOf function. These technologies are useful in customizing HTTP routers, implementing highly customizable systems, and building pluggable components.

Considerations for parameter order in C++ function naming Considerations for parameter order in C++ function naming Apr 24, 2024 pm 04:21 PM

In C++ function naming, it is crucial to consider parameter order to improve readability, reduce errors, and facilitate refactoring. Common parameter order conventions include: action-object, object-action, semantic meaning, and standard library compliance. The optimal order depends on the purpose of the function, parameter types, potential confusion, and language conventions.

How to write efficient and maintainable functions in Java? How to write efficient and maintainable functions in Java? Apr 24, 2024 am 11:33 AM

The key to writing efficient and maintainable Java functions is: keep it simple. Use meaningful naming. Handle special situations. Use appropriate visibility.

Complete collection of excel function formulas Complete collection of excel function formulas May 07, 2024 pm 12:04 PM

1. The SUM function is used to sum the numbers in a column or a group of cells, for example: =SUM(A1:J10). 2. The AVERAGE function is used to calculate the average of the numbers in a column or a group of cells, for example: =AVERAGE(A1:A10). 3. COUNT function, used to count the number of numbers or text in a column or a group of cells, for example: =COUNT(A1:A10) 4. IF function, used to make logical judgments based on specified conditions and return the corresponding result.

Comparison of the advantages and disadvantages of C++ function default parameters and variable parameters Comparison of the advantages and disadvantages of C++ function default parameters and variable parameters Apr 21, 2024 am 10:21 AM

The advantages of default parameters in C++ functions include simplifying calls, enhancing readability, and avoiding errors. The disadvantages are limited flexibility and naming restrictions. Advantages of variadic parameters include unlimited flexibility and dynamic binding. Disadvantages include greater complexity, implicit type conversions, and difficulty in debugging.

What is the difference between custom PHP functions and predefined functions? What is the difference between custom PHP functions and predefined functions? Apr 22, 2024 pm 02:21 PM

The difference between custom PHP functions and predefined functions is: Scope: Custom functions are limited to the scope of their definition, while predefined functions are accessible throughout the script. How to define: Custom functions are defined using the function keyword, while predefined functions are defined by the PHP kernel. Parameter passing: Custom functions receive parameters, while predefined functions may not require parameters. Extensibility: Custom functions can be created as needed, while predefined functions are built-in and cannot be modified.

Advanced usage of reference parameters and pointer parameters in C++ functions Advanced usage of reference parameters and pointer parameters in C++ functions Apr 21, 2024 am 09:39 AM

Reference parameters in C++ functions (essentially variable aliases, modifying the reference modifies the original variable) and pointer parameters (storing the memory address of the original variable, modifying the variable by dereferencing the pointer) have different usages when passing and modifying variables. Reference parameters are often used to modify original variables (especially large structures) to avoid copy overhead when passed to constructors or assignment operators. Pointer parameters are used to flexibly point to memory locations, implement dynamic data structures, or pass null pointers to represent optional parameters.

C++ Function Exception Advanced: Customized Error Handling C++ Function Exception Advanced: Customized Error Handling May 01, 2024 pm 06:39 PM

Exception handling in C++ can be enhanced through custom exception classes that provide specific error messages, contextual information, and perform custom actions based on the error type. Define an exception class inherited from std::exception to provide specific error information. Use the throw keyword to throw a custom exception. Use dynamic_cast in a try-catch block to convert the caught exception to a custom exception type. In the actual case, the open_file function throws a FileNotFoundException exception. Catching and handling the exception can provide a more specific error message.

See all articles