What does a single ampersand ('&') operator do in PHP?

Question

$array1 = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);
print_r(array_filter($array1, "odd"));


function odd($var)
{
    // returns whether the input integer is odd//

    return($var & 1);
}

In the return value what do & operator ?? how it return odd number

Solution

It is bitwise operator AND.

For example, ($a & $b) evaluates both $a and $b is turned "on" (i.e. equal to 1)

See this: http://www.php.net/manual/en/language.operators.bitwise.php

Comments

[Albzi]

Add an explanation? He asked what it does, not just what it is.

[Armel Larcier]

Or just close this one

[Albzi]

Closed anyway @ArmelLarcier

[Raptor]

Marked as close & added explanation :)

[Bhargav Kaklotara]

& is bitwise operators which convert operands to bit-level and then perform operation. let me give an example. here are two operands 5 ( 0101 in bit level ) and 1 ( 0001 in bit level ). AND(&) operation of both the numbers will give o/p of 0001, and that will be same for all the odd numbers. so result will be turned on for all odd numbers.

[Jaskaran singh Rajal]

@BhargavKaklotara Great