Can anyone tell me the difference between $this keyword

Question

What is the use of $this keyword? Output for both cases are same then why should we need to use $this keyword. And where $this keyword is used .

<?php
 class Test
 {
  private $var;
  public function func1()
   {
    $this->var = 1;     
    return $this->var;
   }
  public function func2()
  {
    $var = 2;       
    return $var;
  }
}

$obj = new Test();

echo $obj->func1();
echo $obj ->func2();

?>

Output for both cases 12 and 12.

[Essential reading](http://php.net/manual/en/language.oop5.php) — Mark Baker, Apr 29 '16 at 07:25
Possible duplicate of [What is $this keyword meant for?](http://stackoverflow.com/questions/9974804/what-is-this-keyword-meant-for) or [How to explain 'this' keyword in a best and simple way?](http://stackoverflow.com/questions/2094052/how-to-explain-this-keyword-in-a-best-and-simple-way) — Ani Menon, Apr 29 '16 at 08:27
In your method `func2()`, `$var` is locally scoped, so it only exists inside `func2()` and can't be accessed by any other methods in your class. In method `func1()` you're referencing the class property `$var` by using `$this->var`.... class properties are available to any method in the class — Mark Baker, Apr 29 '16 at 10:31

suibber · Answer 1 · 2016-04-29T07:48:19.127

$this refers to the current objec

$this->var = 1;

the $object->var value has changed to 1.

$var = 2;

the $object->var not changed.

 class Test
 {
  public $var = 0;
  public function func1()
   {
    $this->var = 1;     
    return $this->var;
   }
  public function func2()
  {
    $var = 2;       
    return $var;
  }
}

$obj = new Test();

echo "By default $obj->var is : ".$obj->var;
$obj->func1();
echo "<hr />By func1 $obj->var change to : ".$obj->var;
$obj->func2();
echo "<hr />By func2 $obj->var still is : ".$obj->var;
exit;

The output

By default $obj->var is : 0
By func1 $obj->var change to : 1
By func2 $obj->var still is : 1

`$var` is not an object. its a property ($this->var), or a variable ($var) — DevDonkey, Apr 29 '16 at 07:39

score 0 · Answer 2 · answered Apr 29 '16 at 07:25

0

It's a reference to the current object, it's most commonly used in object oriented code .

it is actually refering instance of current class.

answered Apr 29 '16 at 07:25

Nishant Singh

3,055
11
36
74

Within a function always it will refer to current obj. Are you saying global variable vs local variable. – AskmeBunty Apr 29 '16 at 07:27
yes, its usually the object to which the method belongs, but possibly another object only if the method is called staticaly from the context of a secondary object – Nishant Singh Apr 29 '16 at 07:29

score 0 · Answer 3 · edited May 23 '17 at 12:23

0

In very general terms, we can say that $this is used to reference the current object, you can got a good explanation here What is $this keyword meant for? or How to explain 'this' keyword in a best and simple way?

edited May 23 '17 at 12:23

Community

1
1

answered Apr 29 '16 at 07:28

Ankur Tiwari

2,762
2
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40

Can anyone tell me the difference between $this keyword

3 Answers3