PHP Insert array to associative array at specific position

Question

I want insert one array to another associative array at specific position, but for me the array_splice doesn't work. I want do this:

    $example = [
       'first' => 'element',
       'second' => 'element'];
    $example[] = [
       'third' => 'element',
       'fourth' => 'element'];

Now we have a associative array with inside with two another array. And I want to insert on another array in it, for example between it. It is important, i want to insert to a specific index.

     $insert[] = [
        'insert_first' => 'element',
        'insert_second' => 'element'];
     //I made before it: 
     $index = 1;
     array_splice($example, $index, 0, $insert); //but it doesn't work :(

I want the following result:

array(
 [0] => array(
    'first' => 'element',
    'second' => 'element'
 )
 [1] => array(
    'insert_first' => 'element',
    'insert_second' => 'element'
 )
 [2] => array(
    'third' => 'element',
    'fourth' => 'element'
 )
)

Can somebody help me how can i made it?

Thank, Balázs from Hungary.

Answer 1

$example[] = [
   'first' => 'element',
   'second' => 'element'];
$example[] = [
   'third' => 'element',
   'fourth' => 'element'];
$insert[] = [
    'insert_first' => 'element',
    'insert_second' => 'element'];

$index = 1;
array_splice($example, $index, 0, $insert);
print_r($example);

Gives you :

Array ( 
 [0] => Array ( [first] => element [second] => element ) 
 [1] => Array ( [insert_first] => element [insert_second] => element ) 
 [2] => Array ( [third] => element [fourth] => element ) )

Answer 2

Your original array is incorrect. Correct one:

// Here you have array with one element which is array:
$example = [
   [
       'first' => 'element',
       'second' => 'element'
   ]
];
// Add another element which is array too
$example[] = [
   'third' => 'element',
   'fourth' => 'element'];
// define insert array
$insert[] = [
    'insert_first' => 'element',
    'insert_second' => 'element'
];
$index = 1;
array_splice($example, $index, 0, $insert);