Introduction to post-static binding function after PHP object-oriented, introduction to object-oriented function_PHP tutorial

Introduction to PHP's object-oriented post-static binding function, object-oriented function introduction

This article will introduce the PHP post-static binding function, it is mainly used to solve Reference the statically called class within the inheritance scope.

First look at the following example:

Copy code The code is as follows:
class Person
{

Public static function status()
{
          self::getStatus();
}

Protected static function getStatus()
{
echo "Person is alive";
}

}

class Deceased extends Person
{

Protected static function getStatus()
{
echo "Person is deceased";
}

}

Deceased::status(); //Person is alive

Obviously, the result is not what we expected. This is because self:: depends on the class in which it is defined, not the running class. In order to solve this problem, you may override the status() method in the inherited class. A better solution is that PHP 5.3 added the function of late static binding.

Copy code The code is as follows:
class Person
{

Public static function status()
{
          static::getStatus();
}

Protected static function getStatus()
{
echo "Person is alive";
}

}

class Deceased extends Person
{

Protected static function getStatus()
{
echo "Person is deceased";
}

}

Deceased::status(); //Person is deceased

It can be seen that static:: no longer points to the current class. In fact, it is calculated at runtime, forcing all properties of the final class to be obtained.

Therefore, it is recommended not to use self:: in the future, but to use static::