strtok() splits a string (arg1) into smaller strings
(tokens), with each token being delimited by any character
from arg2. That is, if you
have a string like "This is an example string" you could
tokenize this string into its individual words by using the
space character as the token.
Note that only the first call to strtok uses the string
argument. Every subsequent call to strtok only needs the
token to use, as it keeps track of where it is in the current
string. To start over, or to tokenize a new string you simply
call strtok with the string argument again to initialize it.
Note that you may put multiple tokens in the token parameter.
The string will be tokenized when any one of the characters
in the argument are found.
The behavior when an empty part was found changed with
PHP 4.1.0. The old behavior returned an empty string, while
the new, correct, behavior simply skips the part of the
string:
Also be careful that your tokens may be equal to "0".
This evaluates to FALSE in
conditional expressions.