How to merge/combine two values into single key in the same array

I am not sure what is the appropriate terms to use for my title but just wondering to have below solution where need to merge/combine two values into one within a associative array. For example I have this array:

Array
(
 [1] => Array
    (
        [agent_name_1] => Agent 1
        [agent_phone_1] => 0123456
        [agent_company_1] => My Company
        [agent_email_1] => agent@yahoo.com
        [agent_address_1] => United States
    )

 )

Here I would like to combine company_1 with address_1. So the output should be like this:

Array
(
 [1] => Array
    (
        [agent_name_1] => Agent 1
        [agent_phone_1] => 0123456
        [agent_email_1] => agent@yahoo.com
        [agent_address_1] => My Company, United States
    )

 )

Please someone help me to find out the easiest way to solve this issue.

You would need to loop through the array and modify the corresponding key of the original array.

foreach ($array as $key => $agent) {
  $array[$key]['agent_address_1'] = $agent['agent_company_1'] . ', ' . $agent['agent_address_1'];
  unset($array[$key]['agent_company_1']);
}

Read more about the foreach control structure and how it loops through arrays.

You can use array_map() in your code like this:

<?php

$MyArray[1] = array (
        'agent_name_1' => 'Agent 1',
        'agent_phone_1' => '0123456',
        'agent_company_1' => 'My Company', 
        'agent_email_1' => 'agent@yahoo.com', 
        'agent_address_1' => 'United States'
    );

$array = array_map(function($n) {$n['agent_address_1'] = $n['agent_company_1'] . ', ' . $n['agent_address_1']; unset($n['agent_company_1']); return $n;}, $MyArray);

print_r($array);

Output:

Array
(
    [1] => Array
        (
            [agent_name_1] => Agent 1
            [agent_phone_1] => 0123456
            [agent_email_1] => agent@yahoo.com
            [agent_address_1] => My Company, United States
        )

)