Getting an array key using the max() function

Question

I'm using the max() function to find the largest value in an array. I need a way to return the key of that value. I've tried playing with the array_keys() function, but all I can get that to do is return the largest key of the array. There has to be a way to do this but the php manuals don't mention anything.

Here's a sample of the code I'm using:

$arrCompare = array('CompareOne' => $intOne,
                    'CompareTwo' => $intTwo,
                    'CompareThree' => $intThree,
                    'CompareFour' => $intfour);

$returnThis = max($arrCompare);

I can successfully get the highest value of the array, I just can't get the associated key. Any ideas?

Edit: Just to clarify, using this will not work:

$max_key = max( array_keys( $array ) );

This compares the keys and does nothing with the values in the array.

It seems odd that array_keys() doesn't help you.

Dor
– Dor

2011-08-15 18:12:16 +00:00
Commented Aug 15, 2011 at 18:12 — Dor
– Dor, Commented Aug 15, 2011 at 18:12
@Dor: Using array_keys compares the key values.

Evan Mulawski
– Evan Mulawski

2011-08-15 18:13:22 +00:00
Commented Aug 15, 2011 at 18:13 — Evan Mulawski
– Evan Mulawski, Commented Aug 15, 2011 at 18:13

kravemir · Accepted Answer · 2011-08-15 18:16:42Z

25

array_search function would help you.

$returnThis = array_search(max($arrCompare),$arrCompare);

answered Aug 15, 2011 at 18:16

kravemir

11.1k17 gold badges69 silver badges121 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Funcraft · Accepted Answer · 2015-01-30 06:16:06Z

8

If you need all keys for max value from the source array, you can do:

$keys = array_keys($array, max($array));

answered Jan 30, 2015 at 6:16

Funcraft

1,7092 gold badges15 silver badges23 bronze badges

2 Comments

Tom Auger Over a year ago

Prefer this one, though it's perhaps less obvious than array_search(). I didn't even know that array_keys could take a $search_value as its second argument!

Cagy79 Over a year ago

This returned the SECOND highest key. I went with this answer and that worked in my case : stackoverflow.com/questions/6126066/…

Evan Mulawski · Accepted Answer · 2011-08-15 18:14:39Z

4

Not a one-liner, but it will perform the required task.

function max_key($array)
{
    $max = max($array);
    foreach ($array as $key => $val)
    {
        if ($val == $max) return $key;
    }
}

From http://cherryblossomweb.de/2010/09/26/getting-the-key-of-minimum-or-maximum-value-in-an-array-php/

edited Aug 15, 2011 at 18:14

answered Aug 15, 2011 at 18:09

Evan Mulawski

55.5k16 gold badges122 silver badges147 bronze badges

3 Comments

Adam Wright Over a year ago

Don't recalculate max($array) in each loop iteration - I very much doubt the PHP runtime is smart enough to hoist that out of the loop

Evan Mulawski Over a year ago

@Adam: Wow. Thanks a bunch. I can't believe I missed that when I was reading it!

Cloudkiller Over a year ago

I tested this and it works but it is a bit verbose. I'm going to go with Miro's solution, but thank anyway.

Collectives™ on Stack Overflow

Getting an array key using the max() function

3 Answers 3

Comments

2 Comments

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related