CODEWITHSUNDEEP
phparrays
Joshi
Joshi

Reputation: 2790

array_unshift on multidimensional array

I have this result from var_dump for a multidimensional array:

array (size=6)
  'sambalpur.in.net' => 
    array (size=2)
      'classkey' => string 'indotnet' (length=8)
      'status' => string 'available' (length=9)
  'sambalpur.com' => 
    array (size=2)
      'classkey' => string 'domcno' (length=6)
      'status' => string 'regthroughothers' (length=16)
  'sambalpur.info' => 
    array (size=2)
      'classkey' => string 'dominfo' (length=7)
      'status' => string 'regthroughothers' (length=16)
  'sambalpur.net' => 
    array (size=2)
      'classkey' => string 'dotnet' (length=6)
      'status' => string 'regthroughothers' (length=16)
  'sambalpur.biz' => 
    array (size=2)
      'classkey' => string 'dombiz' (length=6)
      'status' => string 'available' (length=9)
  'sambalpur.in' => 
    array (size=2)
      'classkey' => string 'dotin' (length=5)
      'status' => string 'regthroughothers' (length=16)

Now say I want to shift this specific array to the beginning of array:

'sambalpur.biz' => 
        array (size=2)
          'classkey' => string 'dombiz' (length=6)
          'status' => string 'available' (length=9)

I have tried:

array_unshift($array,array('sambalpur.biz'));

But what I am getting is like this:

array (size=7)
  0 => 
    array (size=1)
      0 => string 'sambalpur.biz' (length=13)
  'sambalpur.in.net' => 
    array (size=2)
      'classkey' => string 'indotnet' (length=8)
      'status' => string 'available' (length=9)
  'sambalpur.com' => 
    array (size=2)
      'classkey' => string 'domcno' (length=6)
      'status' => string 'regthroughothers' (length=16)
  'sambalpur.info' => 
    array (size=2)
      'classkey' => string 'dominfo' (length=7)
      'status' => string 'regthroughothers' (length=16)
  'sambalpur.net' => 
    array (size=2)
      'classkey' => string 'dotnet' (length=6)
      'status' => string 'regthroughothers' (length=16)
  'sambalpur.biz' => 
    array (size=2)
      'classkey' => string 'dombiz' (length=6)
      'status' => string 'available' (length=9)
  'sambalpur.in' => 
    array (size=2)
      'classkey' => string 'dotin' (length=5)
      'status' => string 'regthroughothers' (length=16)

What is the correct way to shift the array?

Upvotes: 2

Views: 799

Answers (3)

AbraCadaver
AbraCadaver

Reputation: 79004

I thought I had done this before but couldn't find a duplicate:

$array = array_splice($array,
                      array_search('sambalpur.biz', array_keys($array)), 1) + $array;
  • Get a numerically indexed array of the keys with array_keys()
  • Search the returned array for sambalpur.biz with array_search()
  • Use the returned index to cut out that element with array_splice()
  • Add that to the existing array

Along the same line as Don't Panic:

$array = array_merge(array('sambalpur.biz' => $array['sambalpur.biz']), $array);

No need to unset as the order of insertion dictates which key overwrites the other so this one overwrites the previous one.

Upvotes: 3

Don't Panic
Don't Panic

Reputation: 41820

You can uksort the array, using the specific key you want to move to the beginning in the comparison function.

$key = 'sambalpur.biz';
uksort($array, function($a, $b) use ($key) {
    if ($a == $key) return -1;
    if ($b == $key) return 1;
    return 0;
});

This should move that item to the beginning without changing the order of the other items.

Another possibility is to remove the child array, and then merge the main array back onto it.

$key = 'sambalpur.biz';
$x = $array[$key];
unset($array[$key]);
$array = array_merge([$key => $x], $array);

Upvotes: 3

georaldc
georaldc

Reputation: 1940

The issue seems to stem from array_unshift() reindexing elements you are passing. If you wanted to prepend your second array to your first array though and preserve indexes, you can use the + operator ($firstArray = $secondArray + $firstArray);

Upvotes: 1

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