get key by position

[The Little Guy]

If I have an array that looks like this:

 

Array ( [4] => 3 [12] => 2 [20] => 1 [23] => 1 [33] => 1 );

 

and I want to return the key 4, how would I get that (4 won't always be the key value)?

[Orio]

Just make sure your array has at least 4 values...

 

<?php

$i = 1;
foreach($arr as $k=>$v)
{
if($i == 4)
{
	$key = $k;
	break;
}
$i++;
}

echo $key;

?>

 

 

Orio.

[GingerRobot]

Well, that depends on what you're trying to achieve. If you want the first key, you can reset() the array, and then use the key() function.

 

If you want to find the key of a particular value, use the array_search() function - however, im not sure this is what you want, since you have 3 elements with a value of 1.

 

Why are we selecting the key 4, rather than any of the others?

 

Edit: I think the difference in the two replies highlights the ambiguity of the question!

[cooldude832]

So based on your sort you want the 4th key you say?

 

you can run a sort that will reindex all the keys and thus $array[3] will always be it, but if the key is importat it won't work, you could try next(next(next($array); after your sort and then say get key on that there is a function for get key

[The Little Guy]

here is what I thought of:

 

<?php foreach($v as $k => $v){$total = $k; break;} ?>

 

Is that a good way?

[Orio]

That will give you the first key. The script in my previous post has an if to check if this is the fourth time the loop runs and that's why it returns the 4th key.

 

Orio.

[The Little Guy]

I want the first key, because I sort the array, and the one I want is first.

[ToonMariner]

if you just used rsort($array) then $array[0] will gove you the highest value. (assuming you sort highest first as that is what your array looks like.)

[Orio]

ohhh I thought the 4th lol

In that case you are right, the code you posted will do the job.

 

Orio.

[The Little Guy]

if you just used rsort($array) then $array[0] will gove you the highest value. (assuming you sort highest first as that is what your array looks like.)

 

that won't work, rsort() reassigns the key values.

[GingerRobot]

Well, either use the code you posted, or use the reset() and then the key() functions. Not sure if there will be any performance difference between the two methods.

[The Little Guy]

OK, well... I decided to use my way... here is the finished product:

 

http://phpsnips.com/snippet.php?id=45

[wildteen88]

If you only want the first element from an array use array_shift:

 

        case 'mode':
            $v = array_count_values($array);
            arsort($v);
            $total = array_shift(array_keys($v));
        break;

 

not a loop.

[Daukan]

This will get the 4th element of an array

<?php
$arr = array ( 4 => 3, 12 => 2, 20 => 1, 23 => 1, 33 => 1 );
$result = array_slice($arr , -2, 1);
echo $result[0];
//returns 1
?>

[Barand]

<?php
$arr = array ( 12 => 2, 20 => 1, 4 => 3, 23 => 1, 33 => 1 );

arsort($arr);                                 // sort descending

echo current(array_keys($arr));       // first key

?>