Question

I’m using this function to search the (highest) array key when a value of userid is found:

function array_search_value($needle,$haystack) {
foreach($haystack as $key => $value) {
    if(in_array($needle, $value)) return $key;
}
  }

My array looks like this (it’s generated by a simple query):

Array
(
[0] => Array
    (
        [0] => 1
        [userid] => 1
        [1] => 2
        [score1] => 2
        [2] => 0
        [score2] => 0
    )

[1] => Array
    (
        [0] => 3
        [userid] => 3
        [1] => 2
        [score1] => 2
        [2] => 2
        [score2] => 2
    )

[2] => Array
    (
        [0] => 4
        [userid] => 4
        [1] => 1
        [score1] => 1
        [2] => 1
        [score2] => 1
    )

[3] => 
)

This code:

echo array_search_value(4, $r)

Returns 2, which is correct.

Looking for 1 gives 0, which is correct.

However, when I search for 2 (which can’t be found), it returns 0.
This, off course, is not correct… What I want it to do is return nothing at all, not 0.
I’ve tried tweeking the function by adding “== true” but that won’t work either.

Anyone know’s how to fix this?

Thanks a lot!

Answer 1

when I search for 2 (which can’t be found), it returns 0. This, off course, is not correct…

Looking at your provided array, it is correct. The value 2 appears in key 0:

[0] => Array
    (
        [0] => 1
        [userid] => 1
        [1] => 2 // here
        [score1] => 2 // and here
        [2] => 0
        [score2] => 0
    )

If you only want to look at the userid key, then you can’t just use in_array(), but have to do such:

<?php
function array_search_value($needle,$haystack) {
foreach($haystack as $key => $value) {
    if($value['userid'] === $needle) return $key;
}
return null; // not found
  }

if (array_search_value(2, $r) === null) { /* doesn't happen */ }