Discuss how the PHP function split() uses regular expressions to split strings_PHP Tutorial

For beginners, mastering the usage of common functions in PHP is the basis for continued learning. Today we will give you a detailed introduction to the instructions
array split ( string $pattern, string $string [, int $limit] )

Tip The
preg_split() function uses Perl-compatible regular expression syntax and is generally a faster alternative to the PHP function split(). If you don't need the power of regular expressions, it's faster to use explode() so you don't incur waste from the regular expression engine.

This function returns a string array, each unit is a string substring separated by the case-sensitive regular expression pattern as a boundary. If limit is set, the returned array contains at most limit cells, with the last cell containing all remaining parts of string. If an error occurs, split() returns FALSE.

Split the first four fields in /etc/passwd:

Example 1839. PHP function split() example

<ol class="dp-xml"><li class="alt"><span><span class="tag"><?</span><span class="tag-name">php</span><span> </span></span></li><li><span>list($user, $pass, $uid, $gid, $extra) =  </span></li><li class="alt"><span>split (":", $passwd_line, 5);  </span></li><li><span class="tag">?></span><span> </span></span></li></ol>

If there are n items in the string that match pattern, the returned array will contain n+1 cells. For example, if pattern is not found, a one-element array is returned. Of course, this is also true if string is empty.

Parse dates that may be separated by slashes, dots, or dashes:

Example 1840. PHP function split() example

<ol class="dp-xml">
<li class="alt"><span><span class="tag"><?</span><span class="tag-name">php</span><span> </span></span></li><li><span>// 分隔符可以是斜线，点，或横线  </span></li><li class="alt"><span>$</span><span class="attribute">date</span><span> = </span><span class="attribute-value">"04/30/1973"</span><span>;  </span></li><li><span>list($month, $day, $year) = split ('[/.-]', $date);  </span></li><li class="alt"><span>echo "Month: $month; Day: $day; Year: $year</span><span class="tag"><</span><span class="tag-name">br</span><span> </span><span class="tag">/></span><span>n";  </span></span></li>
<li>
<span class="tag">?></span><span> </span>
</li>
</ol>

To emulate the similar @chars = split('', $str) behavior in Perl, please refer to the examples in the preg_split() or str_split() functions.

Note that pattern is a regular expression. If the delimiting character you want to use is a special character in a regular expression, you must escape it first. If you think the PHP function split() (or any other regex function) behaves strangely, please read the regex.7 file included in the regex/ subdirectory of the PHP distribution. This file is in manual page format and can be read with a command similar to man /usr/local/src/regex/regex.7