php正则表达式:后视和前瞻和贪婪问题 [英] php regex: lookbehind and lookahead and greediness problem

问题描述

这应该很简单，但我是个菜鸟，我一生都无法弄清楚.我正在尝试使用正则表达式来匹配特殊打开/关闭标签内的文本:[p2][/p2]

This should be simple but I'm a noob and I can't for the life of me figure it out. I'm trying to use regex to match text inside of special open/close tags: [p2][/p2]

所以在本文中:

apple [p2]banana[/p2] grape [p2]lemon[/p2]

它应该匹配banana"和lemon".到目前为止我处理的正则表达式是:

it should match "banana" and "lemon". The regex I've worked up so far is:

(?<=\[p2\]).+(?=\[\/p2\])

但这太贪心了.它匹配以香蕉中的b"开头并以柠檬中的n"结尾，匹配banana[/p2] 葡萄 [p2]lemon.香蕉和柠檬如何搭配?

But this is too greedy. It matches starting with the "b" in banana and ends with the "n" in lemon, matching banana[/p2] grape [p2]lemon. How do I just match banana and lemon?

推荐答案

应该这样做:

(?<=\[p2\]).+?(?=\[\/p2\])

我添加了问号以使量词不贪婪.

I added the question mark to make the quantifier non-greedy.

这篇关于php正则表达式:后视和前瞻和贪婪问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！