When I want to check if something is in the array and get the key back, I use the array_search() function.
Why is it when I compare the function to be exactly equal to true (=== true) it returns false, and when I compare it to not be exactly equal to false (!== false) it returns true?
<?php
if(array_search($value, $array) === true)
{
// Fails
}
if(array_search($value, $array) !== false)
{
// Succeeds
}
?>
Thanks in advance.
array_search returns you needle when a match is found. it returns false only when match is not found. This is why only the opposite works in your case.
Returns the key for needle if it is found in the array, FALSE otherwise.
Late to the party, but wanted to add some context / examples:
array_search will return the key (if the value is found) - which could be 0 - and will return FALSE if the value is not found. It never returns TRUE.
This code may sum it up better:
// test array...
$array = [
0 => 'First Item',
1 => 'Second Item',
'x' => 'Associative Item'
];
// example results:
$key = array_search( 'First Item', $array ); // returns 0
$key = array_search( 'Second Item', $array ); // returns 1
$key = array_search( 'Associative Item', $array ); // returns 'x'
$key = array_search( 'Third Item', $array ); // returns FALSE
Since 0 is a falsey value, you wouldn't want to do something like if ( ! array_search(...) ) {... because it would fail on 0 index items.
Therefore, the way to use it is something like:
$key = array_search( 'Third Item', $array ); // returns FALSE
if ( FALSE !== $key ) {
// item was found, key is in $index, do something here...
}
It's worth mentioning this is also true of functions like strpos and stripos, so it's a good pattern to get in the habit of following.
It will fail because if the call is succesfull it returns the key no true.
false is returned if it isnt found so === false is ok
from the manual:
Returns the key for needle if it is found in the array, FALSE otherwise.
array_search() does not return true.
If will only return false, if it can't find anything, otherwise it will return the key of the matched element.
According to the manual
array_search — Searches the array for a given value and returns the corresponding key if successful ....
Returns the key for needle if it is found in the array, FALSE otherwise.
boolean
boolean. But, no body bothered to read the line after. Ha ha