CODEWITHSUNDEEP
phpusort
John Boe
John Boe

Reputation: 3611

How to sort array by substring? (¨PHP)

I have created method to sort array with values like this: array('regdate','birthday','editdate') which should sort the elements in the way that the elements containing word date should be moved to left like this array('regdate','editdate','birthday')

public function sortColumnsBySubstring($haystack, $substr){
   if ($haystack == $substr) {
          return 0;
      }
    return strpos($substr) !== false ? -1 : 1; 
 }

However it is not clear to me how to make this working. Example which I have found in php manual shows function with no arguments or closures - I use php version 5.2 so I cannot use closures.

All I can think up is this usort($date_cols, $this->sortColumnsBySubstring($value, 'date') but here $value is undefined so it's not solution.

Question is how to implement the function to work correctly?

Upvotes: 1

Views: 1919

Answers (2)

John Boe
John Boe

Reputation: 3611

First solution is to my original question:

function cmp($a, $b)
{
    $adate = (strpos($a, 'date') !== false);
    $bdate = (strpos($b, 'date') !== false);
    if (!($adate ^ $bdate)) return strcmp($a, $b);
    return $adate ? -1 : 1;
}

$a = array('birthday', 'regdate', 'editdate');
usort($a, 'cmp');

Second solution uses splitting into two arrays, sort and then merge them back. I have tried to use more word related to time to identify the values related to time.

 private function getDateColumns(&$array)
 {
 $search_date_columns = array('date','datetime','timestamp','time','edited','changed','modified','created','datum');
 $result = array( array(), array() );
 foreach($array as $v1):
  $found = false;
  foreach($search_date_columns as $v2)
    if ( strpos($v1, $v2)!==false )
      { $found = true; break; }
  if ($found)
    $result[0][] = $v1;
  else
    $result[1][] = $v1;
 endforeach;
 return $result;
 }

Which is implemented like that:

$date_cols = array('regdate','time','editdate','createdate','personal','mojedatum','edited','test','modified','changed','pokus','timestamp','hlava');
$arrays = $this->getDateColumns($date_cols);
rsort($arrays[0]);
$date_cols = array_merge($arrays[0], $arrays[1]); 
unset($arrays);
print_r($date_cols);

Upvotes: 0

Shira
Shira

Reputation: 6560

You need to pass the callback as an array:

usort($date_cols, [$this, 'sortColumnsBySubstring']);

See Callbacks / Callables in PHP docs.

Upvotes: 2

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