Characters Occurrences

gistfile1.php

<?php
// For "aabcd" returns "a: 2, b: 1, c: 1, d: 1"
function charOccurrences($str) {
  $occurrences = [];
  
  $len = strlen($str);
  if ($len > 0) {
    $chars = str_split($str);
    foreach($chars as $char) {
      if (array_key_exists($char, $occurrences)) {
        $occurrences[$char]++;
      } else {
        $occurrences[$char] = 1;
      }
    }
  }
  
  return $occurrences;
}

$occurrences = charOccurrences("aabcd");
print_r($occurrences);