How to get rid of duplicate values from multidimensional array - php

Question

I want to remove duplicate values from multi-dim array, I tried all the possible solutions which is already described but for me, is not working, can anyone please correct it?
Here's my Array:
Array (
[0] => Array (
[0] => element_10
[1] => block_1
[2] => element_4
[3] => element_1
[4] => element_3
)
[1] => Array (
[0] => block_1
[1] => block_2
[2] => element_8
[3] => element_10
[4] => element_12
[5] => element_14
[6] => element_4
[7] => element_2
[8] => element_3
[9] => element_9
[10] => element_13
[11] => element_7
)
)
Where I want the array in this format:
Array (
[0] => Array (
[0] => element_10
[1] => block_1
[2] => element_4
[3] => element_1
[4] => element_3
)
[1] => Array (
[1] => block_2
[2] => element_8
[4] => element_12
[5] => element_14
[7] => element_2
[9] => element_9
[10] => element_13
[11] => element_7
)
)
Ican setup the key indexes later.
I tried:
function multi_unique($array) {
foreach ($array as $k=>$na)
$new[$k] = serialize($na);
$uniq = array_unique($new);
foreach($uniq as $k=>$ser)
$new1[$k] = unserialize($ser);
return ($new1);
}
No Luck, then I tried:
function array_unique_multidimensional($input)
{
$serialized = array_map('serialize', $input);
$unique = array_unique($serialized);
return array_intersect_key($input, $unique);
}
Still same array returning.
I tried this method too:
function super_unique($array)
{
$result = array_map("unserialize", array_unique(array_map("serialize", $array)));
foreach ($result as $key => $value)
{
if ( is_array($value) )
{
$result[$key] = self::super_unique($value);
}
}
return $result;
}
Please help me, I know it's pretty simple I don't know where I'm losing?
Thanks,

Answer 1

You need to iterate over your list of input arrays. For each value in that array, you need to see if you've previously encountered it, so you'll have to keep a super-set of all values across all arrays, which you gradually append to. If a value already exists in the super-set array, you can remove it, otherwise you can append it.
function multi_unique($arrays) {
$all_values = array();
foreach ($arrays as &$array) {
foreach ($array as $index => $value) {
if (in_array($value, $all_values)) {
// We've seen this value previously
unset($array[$index]);
} else {
// First time we've seen this value, let it pass but record it
$all_values[] = $value;
}
}
}
return $arrays;
}
$values = array (
array ( 'element_10', 'block_1', 'element_4', 'element_1', 'element_3',) ,
array ( 'block_1', 'block_2', 'element_8', 'element_10', 'element_12', 'element_14', 'element_4', 'element_2', 'element_3', 'element_9', 'element_13', 'element_7',)
);
var_dump(multi_unique($values));
Output:
array(2) {
[0]=>
array(5) {
[0]=>
string(10) "element_10"
[1]=>
string(7) "block_1"
[2]=>
string(9) "element_4"
[3]=>
string(9) "element_1"
[4]=>
string(9) "element_3"
}
[1]=>
array(8) {
[1]=>
string(7) "block_2"
[2]=>
string(9) "element_8"
[4]=>
string(10) "element_12"
[5]=>
string(10) "element_14"
[7]=>
string(9) "element_2"
[9]=>
string(9) "element_9"
[10]=>
string(10) "element_13"
[11]=>
string(9) "element_7"
}
}

Answer 2

If you just want to remove duplicates from the second entry of your array, use array_diff():
$array[1] = array_diff($array[1], $array[0]);
Iterate if you want to apply it to an arbitrary length.

Answer 3

Why are you using the serialize function.
Use array_diff instead.
A simple would be.
$orginal = array(array(values), array(values), ...);
$copy = $original;
foreach($original as $k => $subArray) {
$tmpCopy = $copy;
unset($tmpCopy[$k]);
unshift($tmpCopy, $subArray);
$tmpCopy = array_values($tmpCopy);
$original[$k] = call_user_func_array('array_diff', $tmpCopy);
}
This works for a two dimensions array.
Hope it helps.