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Usage analysis of __initialize() and class constructor __construct() in ThinkPHP, thinkphp constructor_PHP tutorial
Usage analysis of __initialize() and class constructor __construct() in ThinkPHP, thinkphp constructor_PHP tutorial
Usage analysis of __initialize() and class constructor __construct() in ThinkPHP, thinkphp constructor
This article analyzes __initialize() and the class constructor __construct() in ThinkPHP through examples. Share it with everyone for your reference. The specific analysis is as follows:
__construct in thinkphp cannot be used casually, because your module class inherits the superior class, and the superior class is defined;
1. __initialize() is not a function in the php class. The only constructor of the php class is __construct().
2. Class initialization: If the subclass has its own constructor (__construct()), it will call its own to initialize. If not, it will call the parent class's constructor to initialize itself.
3. When both the subclass and the parent class have __construct() functions, if you want to call the parent class's __constrcut() at the same time when initializing the subclass, you can use parent::__construct in the subclass. ().
If we write two classes, as follows:
Public function __construct()
{
echo 'hello Action';
}
}
class IndexAction extends Action{
Public function __construct()
{
echo 'hello IndexAction';
}
}
$test = new IndexAction;
//output --- hello IndexAction
Obviously, when initializing the subclass IndexAction, it will call its own constructor, so the output is 'hello IndexAction', but change the subclass to:
Public function __initialize()
{
echo 'hello IndexAction';
}
}
Then the output is 'hello Action', because the subclass IndexAction does not have its own constructor. What if I want to call the constructor of the parent class at the same time when initializing the subclass?
Public function __construct()
{
parent::__construct();
echo 'hello IndexAction';
}
}
In this way, two sentences can be output at the same time. Of course, another way is to call the method of the subclass in the parent class.
Public function __construct()
{
If(method_exists($this,'hello'))
$this -> hello();
echo 'hello Action';
}
}
class IndexAction extends Action{
Public function hello()
{
echo 'hello IndexAction';
}
}
In this way, two sentences can be output at the same time, and the method hello() in the subclass here is similar to __initialize() in ThinkPHP.
So, the appearance of __initialize() in ThinkPHP is just to facilitate programmers to avoid frequent use of parent::__construct() when writing subclasses, and at the same time correctly call the constructor of the parent class in the framework, so, we When initializing a subclass in ThnikPHP, use __initialize() instead of __construct(). Of course, you can also modify the __initialize() function to your favorite function name by modifying the framework.
I hope this article will be helpful to everyone’s ThinkPHP framework programming.
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