PHP - Get key name of array value - php

Question

I have an array as the following:
function example() {
/* some stuff here that pushes items with
dynamically created key strings into an array */
return array( // now lets pretend it returns the created array
'firstStringName' => $whatEver,
'secondStringName' => $somethingElse
);
}
$arr = example();
// now I know that $arr contains $arr['firstStringName'];
I need to find out the index of $arr['firstStringName'] so that I am able to loop through array_keys($arr) and return the key string 'firstStringName' by its index. How can I do that?

Answer 1

If you have a value and want to find the key, use array_search() like this:
$arr = array ('first' => 'a', 'second' => 'b', );
$key = array_search ('a', $arr);
$key will now contain the key for value 'a' (that is, 'first').

Answer 2

key($arr);
will return the key value for the current array element
http://uk.php.net/manual/en/function.key.php

Answer 3

If i understand correctly, can't you simply use:
foreach($arr as $key=>$value)
{
echo $key;
}
See PHP manual

Answer 4

If the name's dynamic, then you must have something like
$arr[$key]
which'd mean that $key contains the value of the key.
You can use array_keys() to get ALL the keys of an array, e.g.
$arr = array('a' => 'b', 'c' => 'd')
$x = array_keys($arr);
would give you
$x = array(0 => 'a', 1 => 'c');

Answer 5

Here is another option
$array = [1=>'one', 2=>'two', 3=>'there'];
$array = array_flip($array);
echo $array['one'];

Answer 6

Yes you can infact php is one of the few languages who provide such support..
foreach($arr as $key=>$value)
{
}

Answer 7

if you need to return an array elements with same value, use array_keys() function
$array = array('red' => 1, 'blue' => 1, 'green' => 2);
print_r(array_keys($array, 1));

Answer 8

use array_keys() to get an array of all the unique keys.
Note that an array with named keys like your $arr can also be accessed with numeric indexes, like $arr[0].
http://php.net/manual/en/function.array-keys.php

Answer 9

you can use key function of php to get the key name:
<?php
$array = array(
'fruit1' => 'apple',
'fruit2' => 'orange',
'fruit3' => 'grape',
'fruit4' => 'apple',
'fruit5' => 'apple');
// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name = current($array)) {
if ($fruit_name == 'apple') {
echo key($array).'<br />';
}
next($array);
}
?>
like here : PHP:key - Manual