Counts all the character of a string ascending order

index.php

<?php
  $string = "hello!world!!! rrr";

  echo "<pre>";
  print_r(countChar($string));
  echo "</pre>";

  function countChar($string)
  {
    $explodeString = str_split(strtolower($string));  
    $countChar = array_count_values($explodeString);
    ksort($countChar);

    foreach ($countChar as $key => $value) 
    {
    	$asciiVal=ord($key);
    	if ( 
    		($asciiVal>=ord(' ') && $asciiVal<=ord('/')) || 
    		($asciiVal>=ord(':') && $asciiVal<=ord('`')) || 
    		($asciiVal>=ord('{') && $asciiVal<=ord('~'))) 
    	{
    		unset($countChar[$key]);
    	}
    }

    return $countChar;
  }