CODEWITHSUNDEEP
phparrays
Jasir alwafaa
Jasir alwafaa

Reputation: 586

Sort an array and get the keys

I have two arrays First Array : 

$array_1 = array('50','20','30');

Second Array : 

$array_2 = array('50','30','20');

Second array is generating by applying rsort to $array_1

How can i get another array of key like 

$key_array = ('0','2','1');

Upvotes: 0

Views: 69

Answers (5)

Hiren Makwana
Hiren Makwana

Reputation: 2156

you can use array_keys() function.

$array = array('50','30','20');

$arr_keys = array_keys($array);

Upvotes: 0

Gordon
Gordon

Reputation: 316969

The rsort function will reindex your array keys:

Note: This function assigns new keys to the elements in array. It will remove any existing keys that may have been assigned, rather than just reordering the keys.

You can use arsort instead to maintain index associations. Then you can simply use array_keys to get your desired result.

$unsorted = [50, 20, 30];          // array with unsorted values
$in_reverse = $unsorted;           // create copy because arsort is by reference
arsort($in_reverse);               // do the actual sorting
$keys = array_keys($in_reverse);   // fetch the keys

print_r($keys);

will output

Array
(
    [0] => 0
    [1] => 2
    [2] => 1
)

Upvotes: 0

mario.van.zadel
mario.van.zadel

Reputation: 2949

You can use arsort function instead of rsort to keep the array keys. After that you'll have the possibilty to use array_keys:

$array_1 = array('50','20','30');
$array_2 = $array_1;
arsort($array_2);
$key_array = array_keys($array_2);

Upvotes: 0

rad11
rad11

Reputation: 1561

I think you should use like this to sort with saved indexes:

$array_1 = array('50','20','30');
arsort($array_1);

$key_array = array_keys($array_1);
var_dump($key_array);

output:

array(3) { [0]=> int(0) [1]=> int(2) [2]=> int(1) }

Upvotes: 0

u_mulder
u_mulder

Reputation: 54831

Instead of rsort use arsort, which

Sort an array in reverse order and maintain index association.

After that - use array_keys:

$array_1 = array('50','20','30');
arsort($array_1);
print_r(array_keys($array_1));

Upvotes: 1

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