What does PHP keyword 'var' do?

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.

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

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() {
    }
}

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.

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.

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.

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;
}

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

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.

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

class Sample{
    var $usingVar;
    public $usingPublic;

    function .....

}