几个常用的正则函数

 1 <?php
 2 //preg_match("正则表达式","字符串")用于在字符串中查找匹配项
 3 $email = "postmaster@qiutianjia.com";//简单的邮箱验证，自己不妨试做QQ账号验证,电话号码验证
 4 if (preg_match("/^([a-zA-Z0-9])+([.a-zA-Z0-9_-])*@([.a-zA-Z0-9_-])+([.a-zA-Z0-9_-]+)+([.a-zA-Z0-9_-])$/",$email)){
 5     echo ‘Ok<hr />‘;
 6 }else {
 7     echo ‘Sorry,Error<hr />‘;
 8 }
 9 
10 
11 //preg_quote("字符串") 在有正则表达式语法字符前面加入一个转义字符即\
12 
13 $str = "博客园啊啊啊啊啊啊啊啊，:-(   一 一+ ...";
14 echo preg_quote($str);
15 echo "<hr />";
16 
17 
18 //preg_split("正则","字符串")分割字符串。分割后为数组
19 $php = "......秋........田............嘉";
20 $field = preg_split("/\.{1,}/",$php);
21 foreach($field as $f){
22     echo $f." ";
23 }
24 echo "<hr />";
25 
26 
27 //preg_grep("正则","字符串") 与数组匹配后返回新数组
28 $phpddt = array("php是世界上","php最好","的的的的","语言","php的语言");
29 $item = preg_grep("/^php/",$phpddt);
30 print_r($item);
31 
32 echo "<hr />";
33 
34 
35 //preg_replace("正则","替换内容","原字符串")    很重要，很常用
36 $a = "博客园http://www.cnblogs.com/";  //给http开头的加上超链接
37 echo preg_replace("/http:\/\/(.*)\//","<a href=\"\${0}\">\${0}</a>","$a");
38 
39 
40 ?>