PHP combine two associative arrays into one array

jsteinmann picture jsteinmann · Nov 1, 2012 · Viewed 147.7k times · Source
$array1 = array("$name1" => "$id1");

$array2 = array("$name2" => "$id2", "$name3" => "$id3");

I need a new array combining all together, i.e. it would be

$array3 = array("$name1" => "$id1", "$name2" => "$id2", "$name3" => "$id3");

What is the best way to do this?

Sorry, I forgot, the ids will never match each other, but technically the names could, yet would not be likely, and they all need to be listed in one array. I looked at array_merge but wasn't sure if that was best way to do this. Also, how would you unit test this?

Answer

Samuel Cook picture Samuel Cook · Nov 1, 2012

array_merge() is more efficient but there are a couple of options:

$array1 = array("id1" => "value1");

$array2 = array("id2" => "value2", "id3" => "value3", "id4" => "value4");

$array3 = array_merge($array1, $array2/*, $arrayN, $arrayN*/);
$array4 = $array1 + $array2;

echo '<pre>';
var_dump($array3);
var_dump($array4);
echo '</pre>';


// Results:
    array(4) {
      ["id1"]=>
      string(6) "value1"
      ["id2"]=>
      string(6) "value2"
      ["id3"]=>
      string(6) "value3"
      ["id4"]=>
      string(6) "value4"
    }
    array(4) {
      ["id1"]=>
      string(6) "value1"
      ["id2"]=>
      string(6) "value2"
      ["id3"]=>
      string(6) "value3"
      ["id4"]=>
      string(6) "value4"
    }