How to merge the children of multiple subarrays

I want to concat all my array contained into one using php,

I have this array at the beginning :

{
  "errors": [
    [
      {
        "id": "login1",
        "error": "Invalid"
      },
      {
        "id": "login2",
        "error": "Invalid"
      },
      {
        "id": "login3",
        "error": "Invalid"
      }
    ],
    [],
    [
      {
        "id": "login10", 
        "error": "Invalid"
      },
      {
        "id": "login11", 
        "error": "Invalid"
      }
    ]
  ]
}

And I want to transform it like this :

{
  "errors": [
      {
        "id": "login1",
        "error": "Invalid"
      },
      {
        "id": "login2",
        "error": "Invalid"
      },
      {
        "id": "login3",
        "error": "Invalid"
      },
      {
        "id": "login10", 
        "error": "Invalid"
      },
      {
        "id": "login11", 
        "error": "Invalid"
      }
  ]
}

I try array_push, array_merge, and array_merge_recursive.

My errors array is populate with multiple arrays of logins, I want to have all in one array. How can I do that?

First off, it appears your have JSON data, so you need to json_decode it.

Then it appears you need to remove the first level of hierarchy. Loop through the sub-arrays of errors and merge them all together.

Something like this perhaps:

$errors = [];
foreach($array['errors'] AS $subarray) {
    $errors = array_merge_recursive($errors, $subarray);
}

Working example: https://3v4l.org/JgqgO

You could also do this with something like array_reduce as well.

$errors = array_reduce($array['errors'], function($errors, $subarray) {
   return array_merge_recursive($errors, $subarray); 
}, []);