Description
string 
strtok ( string arg1, string arg2)
     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.
     
| 例子 1. strtok() example | 
<?php$string = "This is\tan example\nstring";
 /* Use tab and newline as tokenizing characters as well  */
 $tok = strtok($string, " \n\t");
 while ($tok) {
 echo "Word=$tok<br />";
 $tok = strtok(" \n\t");
 }
 ?>
 | 
 | 
    
     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:
     
| 例子 2. Old strtok() behavior | 
<?php$first_token  = strtok('/something', '/');
 $second_token = strtok('/');
 var_dump($first_token, $second_token);
 ?>
 | 
 
       Output:
       | string(0) ""
    string(9) "something" | 
 | 
     | 例子 3. New strtok() behavior | 
<?php$first_token  = strtok('/something', '/');
 $second_token = strtok('/');
 var_dump($first_token, $second_token);
 ?>
 | 
 
       Output:
       | string(9) "something"
    bool(false) | 
 | 
    
     Also be careful that your tokens may be equal to "0". This
     evaluates to FALSE in conditional expressions.
    
     See also split() and
     explode().