In php, we usually declare a class first, and then use this class to instantiate objects!
Usage:
$this means the specific object after instantiation.
$this->Indicates using the attributes or methods of this class within the class itself.
The ‘->’ symbol is the “infix dereference operator”. In other words, it is a method that calls a subroutine whose parameters are passed by reference (among other things, of course). As we mentioned above, when calling PHP functions, most parameters are passed by reference.
For example, we declare a User class! It only contains one attribute $name
<?php
class User
{
public $_name;
}
?>Now, we add a method to the User class.
<?php
class User
{
public $name;
function getName()
{
echo $this->name;
}
}
//如何使用呢？
$user1 = new User();
$user1->name = '张三';
$user1->getName(); //这里就会输出张三！
$user2 = new User();
$user2->name = '李四';
$user2->getName(); //这里会输出李四！
?>Two User objects are created above. They are $user1 and $user2 respectively.
When $user1->getName() is called, the code in the User class above echo $this->name ; is equivalent to echo $user1->name;
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