PHP字符串拆分

I'm new to PHP. I was reading this: http://php.net/manual/en/ref.strings.php however I'm looking for additional clarification.

I know in python I can call .split("...") as well as in Java.

So I found chunk_split, str_split, and explode. What are the reasons for using each? From what I was reading I was under the impression that each could be used for the same task. Is there an explicit advantage for using one over the other?

I'm looking to split a url to get the "Base" (not sure what else to call it)

Ex:

http://www.stackoverflow.com/questions/ask

I was thinking I could cut off the front with if statements

if = http:// or http://www. or www. etc... #pseudo

Then cut by "/" chars and take the front.

Which function is best purposed for this?

The function you're after is parse_url():

<?php

$url = 'http://www.stackoverflow.com/questions/ask';

$parsed_url = parse_url($url);

echo '<pre>';
print_r($parsed_url);
echo '</pre>';

output:

Array
(
    [scheme] => http
    [host] => www.stackoverflow.com
    [path] => /questions/ask
)