Getting key from array when value is known.

[padders]

This seems like it should be easy but i can't do it.

Say i had:

$array = array('10' => 'Yes', '20' => 'No');

I have the value "No" and i want to get the number 20 from the array.

Don't worry about duplicates, if there are any they will always have the same id.

Anybody know how to do this. I tried php.net and there was a function someone had submitted to use this but I have found it unreliable. Works sometimes but not others and I don't know why.

I include it here:

    function array_binary_search($needle, $haystack) {
$l=0;
$u=count($haystack);
$m=($l+$u)/2;
$j=0;
$k=1;

while($l <= $u) {
    $j++;
    $k++;
    if ( $needle > $haystack[$m] )
    $l = floor($m + 1);
    if ( $needle <= $haystack[$m] )
    $u = $m - 1;
    $m = ($l+$u)/2;
}

if ($haystack[$l] != $t)
return -1;
return $l;
} 

[zoordaan]

The array_keys function should work for this.

http://www.php.net/manual/en/function.array-keys.php

[padders]

doh. i was trying to use array_search

http://www.php.net/manual/en/function.array-search.php

thanks