How to merge array of arrays by key in php? -

so questions of nature have been asked 1000 times on stack overflow, none of them i've searched through far address issue i'm having. have 2 arrays this:

$cupcake_sales = [    ['date' => '05/09/1992', 'num_cupcakes_sold' => 30 ],    ['date' => '05/11/1992', 'num_cupcakes_sold' => 25 ], ]; 

and array this:

$cupcake_revenue = [     ['date' => '05/10/1992', 'revenue' => '$40'],     ['date' => '05/11/1992', 'revenue' => '$100'], ]; 

what need array this:

$cupcake_sales_revenue = [     ['date' => '05/09/1992', 'num_cupcakes_sold' => 30],     ['date' => '05/10/1992', 'num_cupcakes_sold' => 25, 'revenue' => '$40'],      ['date' => '05/11/1992', 'revenue' => '$100'], ]; 

any way of doing this?

this should work you:

(here loop through both arrays array_map() , if date same merge 2 arrays array_merge() , assign results array. if different append both arrays result array in current iteration.)

<?php      $cupcake_sales_revenue = [];      array_map(function($v1, $v2)use(&$cupcake_sales_revenue){         if($v1["date"] == $v2["date"]) {             $cupcake_sales_revenue[] = array_merge($v1, $v2);         } else {             $cupcake_sales_revenue[] = $v1;             $cupcake_sales_revenue[] = $v2;         }     }, $cupcake_sales, $cupcake_revenue);      print_r($cupcake_sales_revenue);   ?> 

output:

array (     [0] => array         (             [date] => 05/09/1992             [num_cupcakes_sold] => 30         )      [1] => array         (             [date] => 05/10/1992             [revenue] => $40         )      [2] => array         (             [date] => 05/11/1992             [num_cupcakes_sold] => 25             [revenue] => $100         )  )