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Home Backend Development PHP Tutorial 正则表达式 - 一句php解析html页面的脚本问题

正则表达式 - 一句php解析html页面的脚本问题

Jun 06, 2016 pm 08:48 PM
php regular expression

preg_match_all('/<td width="20%" align="left">.*<\/td>/u',$html,$match,PREG_OFFSET_CAPTURE);
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主要是其中的正则表达式没看明白,开头的/和结尾的/u是代表其中的内容是unicode么?不需要用\转译这两个/

然后PREG_OFFSET_CAPTURE这个flag到底又什么用,看了文档还是没怎么明白,希望各位大大指教

回复内容:

preg_match_all('/<td width="20%" align="left">.*<\/td>/u',$html,$match,PREG_OFFSET_CAPTURE);
Copy after login
Copy after login

主要是其中的正则表达式没看明白,开头的/和结尾的/u是代表其中的内容是unicode么?不需要用\转译这两个/

然后PREG_OFFSET_CAPTURE这个flag到底又什么用,看了文档还是没怎么明白,希望各位大大指教

/ / 是表示中间内容是表达式。 u 是修饰符,定义这个模式字符串被认为是utf-8的。

http://www.php.net/manual/zh/reference.pcre.pattern.modifiers.php

嗯,//标示正则表达式开始结束,u是修饰符,具体可见 http://www.php.net/manual/zh/reference.pcre.pattern.modifiers.php

Flag结果排序方式,结合实际测试可以更清楚。

PREGPATTERNORDER 结果排序为$matches[0]保存完整的所有匹配, $matches[1] 保存第一个()的所有匹配,以此类推

PREGSETORDER 结果排序为$matches[0]包含第一次匹配得到的所有匹配(包含子组), $matches[1]是包含第二次匹配到的所有匹配(包含子组)的数组,以此类推。

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