What is the difference between array_merge and array + array in PHP?

Both get the union of arrays, but array_merge() overwrites duplicate non_numeric keys. Let us now see an example of the array+array−

Example

 Live Demo

<?php    $arr1 = array( "p"=>"150", "q"=>"100", "r"=>"120", "s"=>"110");    $arr2 = array("t"=>"115", "u"=>"103", "v"=>"105", "w"=>"125" );    var_dump ($arr1 + $arr2); ?>

Output

This will produce the following output−

array(8) {    ["p"]=>    string(3) "150"    ["q"]=>    string(3) "100"    ["r"]=>    string(3) "120"    ["s"]=>    string(3) "110"    ["t"]=>    string(3) "115"    ["u"]=>    string(3) "103"    ["v"]=>    string(3) "105"    ["w"]=>    string(3) "125" }

Example

Let us now see an example of array_merge() in PHP−

 Live Demo

<?php    $arr1 = array( "p"=>"150", "q"=>"100", "r"=>"120", "s"=>"110");    $arr2 = array("t"=>"115", "u"=>"110", "v"=>"105", "w"=>"100" );    var_dump (array_merge($arr1, $arr2)); ?>

Output

This will produce the following output−

array(8) {    ["p"]=>    string(3) "150"    ["q"]=>    string(3) "100"    ["r"]=>    string(3) "120"    ["s"]=>    string(3) "110"    ["t"]=>    string(3) "115"    ["u"]=>    string(3) "110"    ["v"]=>    string(3) "105"    ["w"]=>    string(3) "100" }