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

RTFM: http://www.php.net/manual/en/language.operators.bitwise.php — CBroe, Mar 13 '14 at 10:51
The usage of `&` here has nothing to do with arrays .. consider if there was no array and odd was called as `odd(13)` and `odd(42)`. — user2864740, Mar 13 '14 at 10:52
goto https://www.php.net/manual/en/function.array-filter.php -> User Contributed Notes -> searchBy("nicolaj")->read() — habibun, Jun 02 '21 at 10:43

score 9 · Answer 1 · answered Mar 13 '14 at 10:51

9

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

answered Mar 13 '14 at 10:51

Raptor

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7

Add an explanation? He asked what it does, not just what it is. – Albzi Mar 13 '14 at 10:52
2

Or just close this one – Armel Larcier Mar 13 '14 at 10:52
Closed anyway @ArmelLarcier – Albzi Mar 13 '14 at 10:52
Marked as close & added explanation :) – Raptor Mar 13 '14 at 10:55
3

& 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. – Bhargav Kaklotara Oct 01 '19 at 11:23
@BhargavKaklotara Great – Jaskaran singh Rajal Jun 29 '21 at 08:21

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

1 Answers1