Skip repeating array and reverse order of the array

Question

I have this array. In this I want to skip the value for reverse data.

$data = array(
    array(2, 1),
    array(1, 2),
    array(1, 2),
    array(2, 1),
    array(2, 3),
    array(3, 2),
    array(4, 5)
);

I want to skip the values:

array(1,2)
array(1,2)
array(2,1)
array(3,2)

And I want the result array to be like this:

array(
    array(2, 1),
    array(2, 3),
    array(4, 5)
);

You mean you want to eliminate duplicate values, and then sort the array? Or you you mean simply remove individual values from the array? Can you explain what you mean by "skip" and what rules determine what elements are to be skipped? — Mark Baker, Aug 08 '15 at 10:05
Yes, I want to eliminate the duplicate value as well as eliminate the reverse order of the array. — madhu, Aug 08 '15 at 10:07
He wants to delete the duplicate sub-arrays, even if the elements in the sub-array are in a different order. Basically unique sub-arrays - keys not important. — Dan Belden, Aug 08 '15 at 10:08

Mark Baker · Accepted Answer · 2015-08-08T10:45:14.993

2

$data = [[2,1], [1,2], [1,2], [2,1], [2,3], [3,2], [4,5]];

$data = array_map(
    function($value) {
        sort($value);
        return serialize($value);
    },
    $data
);

$data = array_unique($data);
$data = array_map('unserialize', $data);
array_walk($data, 'sort');

var_dump($data);

Demo

EDIT

As per arbogast's comment, this can be simplified even further, eliminating the serialize/unserialize steps:

$data = [[2,1], [1,2], [1,2], [2,1], [2,3], [3,2], [4,5]];

array_walk($data, 'sort');
$data = array_unique($data, SORT_REGULAR);

var_dump($data);

Demo

edited Aug 08 '15 at 10:45

answered Aug 08 '15 at 10:14

Mark Baker

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This does sort the sub-arrays though so not 100%. – Dan Belden Aug 08 '15 at 10:26
Well you could always skip that last line `array_walk($data, 'sort');` if you didn't want to sort the subarrays – Mark Baker Aug 08 '15 at 10:28
You can have same result if you use array_unique($data, SORT_REGULAR); then you don't have to use serialization. – arbogastes Aug 08 '15 at 10:30
@arbogast - thanks for the tip, I wasn't aware of that flag for `array_unique()`.... useful to know – Mark Baker Aug 08 '15 at 10:50
@Mark Baker Glad I could help. – arbogastes Aug 08 '15 at 10:52

hamed · Answer 2 · 2015-08-08T10:24:52.433

Try this:

function filterArray($data)
{
      $result = array();
      array_push($result, $data[0]); //You can always add first item without performing any check
      for($i=1; $i<count($data); $i++)
      {
          $allowAdd = true;
          foreach($result as $res)
          {
              if(($res == $data[$i]) || ($res[0] = $data[$i][1] && $res[1] = $data[$i][0]))
              {
                  $allowAdd = false;
                  break;
              }
          }
          if($allowAdd)
            array_push($result, $data[$i]);
     }
     return $result;
}

Now, when you call filterArray($data), this will return you the filtered result.

Skip repeating array and reverse order of the array

2 Answers2