How to sort mutidimensional array by its key in php

Question

I have a mutidimensional array something like this

<?php 

$data2[3][1]=6;
$data2[9][3]=4;
$data2[9][2]=18;
$data2[4][2]=24;
$data2[4][0]=12;
$data2[4][1]=14;

?>

I want to sort this array by its key, so that it looks like this

$data2[3][1]=6;
$data2[4][0]=12;
$data2[4][1]=14;
$data2[4][2]=24;
$data2[9][2]=18;
$data2[9][3]=4;

used this

foreach ($data2 as $k[]){
ksort($k);

}

print_r($k);

but not working.

You're sorting the sub arrays. You just need the parent array sorted, so ksort() should do the trick. If you awnt the sub-arrays sorted too,t hen you'll need a custom function, which is what usort() is for. — Marc B
– Marc B, Commented Jan 21, 2014 at 15:32

The Humble Rat · Accepted Answer · 2014-01-21 15:35:28Z

1

The loop is necessary for the next level down

$data2[3][1]=6;
$data2[9][3]=4;
$data2[9][2]=18;
$data2[4][2]=24;
$data2[4][0]=12;
$data2[4][1]=14;

foreach($data2 as $key=>$data)
{
   ksort($data2[$key]);
}

ksort($data2);

echo '<pre>';
print_r($data2);
echo '</pre>';

This will output

Array
(
    [3] => Array
        (
            [1] => 6
        )

    [4] => Array
        (
            [0] => 12
            [1] => 14
            [2] => 24
        )

    [9] => Array
        (
            [2] => 18
            [3] => 4
        )

)

answered Jan 21, 2014 at 15:35

The Humble Rat

4,7468 gold badges44 silver badges74 bronze badges

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

Comments

Dutchie432 · Accepted Answer · 2014-01-21 15:35:04Z

0

I think you want to first sort the array, then the sub-arrays within.

ksort($data2); //Sort Array

foreach ($data2 as &$k){
    ksort($k); //Sort Each Sub-Array
}

Updated based on Rocket Hazmat's comment

answered Jan 21, 2014 at 15:35

Dutchie432

29.3k20 gold badges94 silver badges110 bronze badges

8 Comments

gen_Eric Over a year ago

foreach ($data2 as $k){ needs to be foreach ($data2 as &$k){ :-)

Dutchie432 Over a year ago

You are right, but would you care to explain? $k is passed as a normal array, no?

The Humble Rat Over a year ago

@RocketHazmat I am interested in this also.

gen_Eric Over a year ago

What do you mean by "normal array"? When you foreach you are operating on a copy of the array. So when you ksort($k), you are sorting it, but you are not updating the original array. &$k makes $k a reference to the element in the original array. Now when you update $k, it's updated in the original array.

Dutchie432 Over a year ago

@RocketHazmat Thank you for the explanation. Running this code proves you're correct and my answer was updated. Makes sense. I would have used Humble Rat's for as opposed to foreach myself, but I was copying OP's code. Thanks for clarifying.

|

Collectives™ on Stack Overflow

How to sort mutidimensional array by its key in php

2 Answers 2

Comments

8 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

8 Comments

Your Answer

Sign up or log in

Post as a guest

Related