Question

After I’ve asked for a method to combine 2 arrays I got several answers as you can find here:

Array combine into associative array

I’ve implemented the accepted answer but, as the author warned, I’ve run into a “duplicate keys” problem.

This is the code I’m using:

$a = array(4=>3,5=>3);
$b = array(array(0=>0,1=>4,2=>10,3=>1000),
           array(0=>0,1=>40,2=>100,3=>2000),
           array(4=>10)
          );

$c = array();
foreach($b as $tmp) {
    $c[] = $a+$tmp;
}

var_dump($c);

But it returns an array like this one:

Array (
    [0] => Array (
        [3] => 1 
        [5] => 1 
        [6] => 0 
        [7] => 0 
        [8] => 0
        )
    [1] => Array (
        [3] => 1 
        [5] => 1 
        [6] => 0 
        [7] => 0 
        [8] => 0
        ) 
    [2] => Array (
        [3] => 1 
        [5] => 1 
        [6] => 1 
        [7] => 0 
        [8] => 0
        )
    [3] => Array ( 
        [3] => 1 
        [5] => 1 
        [6] => 1 
        [7] => 0 
        [8] => 0
        )
    [4] =>...

As you can see the key 0 is the same as key 1.. etc.

How can I solve this?

Thanks in advance.

Answer 1

Sorry, my original answer displayed a complete lack of reading comprehension skills. If I correctly understand what you’re trying to accomplish this should do the trick:

$unique = array();
foreach ($c as $arr) {
  if ( ! in_array($arr, $unique)) {
    $unique[] = $arr;
  }
}

var_dump($unique);

This builds up a unique array by iterating over the original array and adding new elements as it encounters them.