Question

I have an array for example ("1:2","5:90","7:12",1:70,"29:60") Wherein ID and Qty are separated by a ‘:’ (colon), what I want to do is when there’s a duplicate of IDs the program will add the qty and return the new set of arrays so in the example it will become ("1:72","5:90","7:12","29:60").

Ex.2

("1:2","5:90","7:12","1:70","29:60","1:5") 

becomes

("1:77","5:90","7:12","29:60").

Answer 1

<?php

$arr = array("1:2","5:90","7:12", "1:70","29:60");

$newArr = array();

foreach($arr as $key => $value) {

  list($id, $quantity) = explode(':', $value);

  if(isset($newArr[$id]))
    $newArr[$id] += $quantity;
  else
    $newArr[$id] = $quantity;

}

foreach($newArr as $key => $value) {
  $newArr[$key] = "$key:$value";
}

print_r($newArr);