given string of book count the words using php

gistfile1.txt

<?php
$book = 'Some Text Is Here Text Is Text Text characters';

$book_words = explode(" ", $book);

$counted_words = array();

foreach ( $book_words as $word ) {
  if ( array_key_exists($word, $counted_words) ) {
    $counted_words[$word]++;
  } else {
    $counted_words[$word] = 1;
  } 
}

foreach ( $counted_words as $word => $count ) { 
  echo $word. " : ". $count. "<br>";
}

?>