What does PHP keyword 'var' do?

Question

This is probably a very trivial question, but I haven't been able to find the answer neither through web search engines, nor on php.net. Please just direct me to where I can read about this, if you haven't got time to explain.

What does the 'var' keyword mean in PHP?
Are there any differences between PHP4 and PHP5?

I guess when you asked this question on July 30th, 2009, this had not been published yet at http://php.net/manual/en/language.oop5.visibility.php?: "Note: The PHP 4 method of declaring a variable with the var keyword is still supported for compatibility reasons (as a synonym for the public keyword). In PHP 5 before 5.1.3, its usage would generate an E_STRICT warning." Or maybe you had not found it. But the answer is clearly stated at php.net. — Jaime Montoya, Jun 16 '17 at 20:21
That's really amazing to see what journeys PHP has passed these years! — Mehrdad Shokri, Mar 23 '20 at 22:29

score 394 · Accepted Answer · edited Apr 10 '15 at 13:03

394

It's for declaring class member variables in PHP4, and is no longer needed. It will work in PHP5, but will raise an E_STRICT warning in PHP from version 5.0.0 up to version 5.1.2, as of when it was deprecated. Since PHP 5.3, var has been un-deprecated and is a synonym for 'public'.

Example usage:

class foo {
    var $x = 'y'; // or you can use public like...
    public $x = 'y'; //this is also a class member variables.
    function bar() {
    }
}

edited Apr 10 '15 at 13:03

Abraham Philip

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answered Jul 30 '09 at 11:54

karim79

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_"Note: The PHP 4 method of declaring a variable with the `var` keyword is still supported for compatibility reasons (as a synonym for the `public` keyword). In PHP 5 before 5.1.3, its usage would generate an `E_STRICT` warning."_ http://php.net/manual/en/language.oop5.visibility.php EDIT: I just saw that is has already been quoted [in another answer](http://stackoverflow.com/a/3844703/517705). But you should edit yours accordingly. – Sk8erPeter Jan 12 '13 at 10:38
This implies that it is *necessary* to use the `public` keyword with for a member variable. Is that true? Can't one simply put `$x;`? – limeandcoconut Feb 03 '15 at 20:55
1

so is it recommended to just stick with public/private and ignoring var entirely since we aren't worried about working with deprecated versions of PHP? – rolling_codes Jul 05 '15 at 17:46
2

As of 2019: https://www.php-fig.org/psr/psr-12/#43-properties-and-constants states that `var` must not be used, and visibility must be declared on all properties. – Charles Wood Nov 11 '19 at 14:23

score 79 · Answer 2 · answered Jul 30 '09 at 11:55

79

The var keyword is used to declare variables in a class in PHP 4:

class Foo {
    var $bar;
}

With PHP 5 property and method visibility (public, protected and private) was introduced and thus var is deprecated.

answered Jul 30 '09 at 11:55

Gumbo

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In PHP 5.3 `var` is de-deprecated :) – Ionuț G. Stan Jul 30 '09 at 11:58
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If it's de-deprecated, what's the best practice now in 5.3 - to use it or not to use it? Can you use it like `private var $foo = 'bar';`? – Tom Auger May 11 '11 at 15:01
1

Anyone know why it was de-deprecated? – Simon East May 16 '12 at 23:32
19

It was undeprecated [in 5.1.3](http://www.php.net/releases/5_1_3.php) - the only reasons given are ["for compatibility reasons"](http://www.php.net/manual/en/language.oop5.visibility.php). I think best practice is to use it only if you need to be compatible with PHP 4. Certainly don't do `private var` - that will break things real quick, as `var` is just a synonym for `public` in PHP 5. – cincodenada Sep 19 '12 at 23:31
2

`var` is not a true synonym for `public` as it cannot be used for declaring static members or constants. – Colin O'Dell Mar 31 '16 at 17:05
@Colin O'Dell's comment is the best =) – mzalazar Jun 04 '19 at 23:46

score 27 · Answer 3 · edited Aug 02 '19 at 11:37

27

I quote from http://www.php.net/manual/en/language.oop5.visibility.php

Note: The PHP 4 method of declaring a variable with the var keyword is still supported for compatibility reasons (as a synonym for the public keyword). In PHP 5 before 5.1.3, its usage would generate an E_STRICT warning.

edited Aug 02 '19 at 11:37

Roshan

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answered Oct 02 '10 at 06:52

taatparya

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I did tests. No returned E_STRICT ! http://sandbox.onlinephpfunctions.com/code/84652903a92588c23085e688803abfaf0c26a822 – Wallace Vizerra Jul 13 '15 at 12:07
1

@WallacedeSouza, that's because you have used PHP 7 in your example. It was invalid only in versions 5.0 - 5.1.3 – May 24 '17 at 13:58

Webeng · Answer 4 · 2016-05-24T06:18:14.443

8

Answer: From php 5.3 and >, the var keyword is equivalent to public when declaring variables inside a class.

class myClass {
  var $x;
}

is the same as (for php 5.3 and >):

class myClass {
  public $x;
}

History: It was previously the norm for declaring variables in classes, though later became depreciated, but later (PHP 5.3) it became un-depreciated.

edited May 24 '16 at 06:18

answered May 24 '16 at 05:48

Webeng

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kta · Answer 5 · 2016-12-29T08:12:10.183

7

So basically it is an old style and do not use it for newer version of PHP. Better to use Public keyword instead;if you are not in love with var keyword. So instead of using

class Test {
    var $name;
}

Use

class Test {
   public $name;
}

edited Dec 29 '16 at 08:12

answered Dec 29 '16 at 08:07

kta

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why you say that? is there news of `var` being deprecated that I havent heard? the two should be synonymous – NappingRabbit Jan 18 '18 at 17:43
1

From the PHP manual: "The PHP 4 method of declaring a variable with the var keyword is still supported for compatibility reasons (as a synonym for the public keyword)." https://www.php.net/manual/en/language.oop5.visibility.php – Tomark Mar 30 '20 at 11:00

score 2 · Answer 6 · answered Jul 26 '17 at 13:34

2

var is used like public .if a varable is declared like this in a class var $a; if means its scope is public for the class. in simplea words var ~public

var $a;
public

answered Jul 26 '17 at 13:34

kumar

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score 2 · Answer 7 · answered Oct 17 '19 at 06:51

2

In PHP7.3 still working...

https://www.php.net/manual/en/language.oop5.visibility.php

If declared using var, the property will be defined as public.

answered Oct 17 '19 at 06:51

xayer

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score 1 · Answer 8 · answered Jan 18 '18 at 17:46

1

here and now in 2018 using var for variable declaration is synonymous with public as in

class Sample{
    var $usingVar;
    public $usingPublic;

    function .....

}

answered Jan 18 '18 at 17:46

NappingRabbit

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What does PHP keyword 'var' do?

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