str_word_count - 문자열에서 사용한 단어에 대한 정보 반환

<?php

$str = "Hello friend, you're looking good today!";

$a  = str_word_count($str, 1);
$b  = str_word_count($str, 2);
$c  = str_word_count($str);

print_r($a);
print_r($b);
echo $c;
?>

Array
(
    [0] => Hello
    [1] => friend
    [2] => you're
    [3] => looking
    [4] => good
    [5] => today
)

Array
(
    [0] => Hello
    [6] => friend
    [14] => you're
    [29] => looking
    [46] => good
    [51] => today
)

6