Let’s imagine you have a huge array, with say couple ten thousands of elements and you want to remove any duplicates entries in this array. As PHP programmer you’ll be thinking of array_unique. For a “small” sized array and one dimensional array this one does the trick.
I have some nice snippets which cover multi dimensional and/or huge sized array.
First: you have a huge, one dimensional array.
|
1 |
array_flip(array_flip(array_reverse($input,true))) |
This one works only on one dimensional array. The key of the last element will be preserved and the keys are not sorted
Second: for a huge, multi dimensional array
|
1 2 3 4 5 6 7 8 9 |
function super_unique($array) { $result = array_map("unserialize", array_unique(array_map("serialize", $array))); foreach ($result as $key => $value) { if ( is_array($value) ) { $result[$key] = super_unique($value); } } return $result; } |
sources:
- http://dk.php.net/manual/en/function.array-unique.php#97285
- http://www.puremango.co.uk/2010/06/fast-php-array_unique-for-removing-duplicates/