array_splice() - Numerical Offsets of Associative Arrays - php

Question

I'm trying to do something but I can't find any solution, I'm also having some trouble putting it into works so here is a sample code, maybe it'll be enough to demonstrate what I'm aiming for:
$input = array
(
'who' => 'me',
'what' => 'car',
'more' => 'car',
'when' => 'today',
);
Now, I want to use array_splice() to remove (and return) one element from the array:
$spliced = key(array_splice($input, 2, 1)); // I'm only interested in the key...
The above will remove and return 1 element (third argument) from $input (first argument), at offset 2 (second argument), so $spliced will hold the value more.
I'll be iterating over $input with a foreach loop, I know the key to be spliced but the problem is I don't know its numerical offset and since array_splice only accepts integers I don't know what to do.
A very dull example:
$result = array();
foreach ($input as $key => $value)
{
if ($key == 'more')
{
// Remove the index "more" from $input and add it to $result.
$result[] = key(array_splice($input, 2 /* How do I know its 2? */, 1));
}
}
I first though of using array_search() but it's pointless since it'll return the associative index....
How do I determine the numerical offset of a associative index?

Answer 1

Just grabbing and unsetting the value is a much better approach (and likely faster too), but anyway, you can just count along
$result = array();
$idx = 0; // init offset
foreach ($input as $key => $value)
{
if ($key == 'more')
{
// Remove the index "more" from $input and add it to $result.
$result[] = key(array_splice($input, $idx, 1));
}
$idx++; // count offset
}
print_R($result);
print_R($input);
gives
Array
(
[0] => more
)
Array
(
[who] => me
[what] => car
[when] => today
)
BUT Technically speaking an associative key has no numerical index. If the input array was
$input = array
(
'who' => 'me',
'what' => 'car',
'more' => 'car',
'when' => 'today',
'foo', 'bar', 'baz'
);
then index 2 is "baz". But since array_slice accepts an offset, which is not the same as a numeric key, it uses the element found at that position in the array (in order the elements appear), which is why counting along works.
On a sidenote, with numeric keys in the array, you'd get funny results, because you are testing for equality instead of identity. Make it $key === 'more' instead to prevent 'more' getting typecasted. Since associative keys are unique you could also return after 'more' was found, because checking subsequent keys is pointless. But really:
if(array_key_exists('more', $input)) unset($input['more']);

Answer 2

I found the solution:
$offset = array_search('more', array_keys($input)); // 2
Even with "funny" arrays, such as:
$input = array
(
'who' => 'me',
'what' => 'car',
'more' => 'car',
'when' => 'today',
'foo', 'bar', 'baz'
);
This:
echo '<pre>';
print_r(array_keys($input));
echo '</pre>';
Correctly outputs this:
Array
(
[0] => who
[1] => what
[2] => more
[3] => when
[4] => 0
[5] => 1
[6] => 2
)
It's a trivial solution but somewhat obscure to get there.
I appreciate all the help from everyone. =)

Answer 3

$i = 0;
foreach ($input as $key => $value)
{
if ($key == 'more')
{
// Remove the index "more" from $input and add it to $result.
$result[] = key(array_splice($input, $i , 1));
}
$i++;
}