正则表达式匹配第一个和最后一个字符

正则表达式匹配第一个和最后一个字符

本文介绍了正则表达式匹配第一个和最后一个字符的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述



我知道这是匹配第一个字符:

  / ^ [az] / i 

但是如何才能检查最后一个字符?这是:

  / ^ [az] [az] $ / i 
pre>

不工作。我怀疑两个条款之间应该有什么,但我不知道什么!



任何帮助将不胜感激。

解决方案

下面的正则表达式将匹配以alpha字符开头和结尾的字符串。

  / ^ [az]。* [az] $ / igm 

a 字符串也以字母开头和结尾,对吧?那么你必须使用下面的正则表达式。

  / ^ [az](。* [az])?$ / igm 



说明:

 code> ^#表示开始一行。 
[a-z]#alphabatic character。
。*#任意字符0次以上。
[a-z]#alphabatic character。
$#一行结束。
我#不区分大小写的匹配。
g#global。
m#multiline


I'm trying to use regex to check that the first and last characters in a string are alpha characters between a-z.

I know this matches the first character:

/^[a-z]/i

but how do I then check for the last character as well? This:

/^[a-z][a-z]$/i

does not work. And I suspect there should be something in between the two clauses but I don't know what!

Any help would be much appreciated.

解决方案

The below regex will match the strings that starts and ends with alpha character.

/^[a-z].*[a-z]$/igm

a string also starts and endswith alpha character , right? Then you have to use the below regex.

/^[a-z](.*[a-z])?$/igm

DEMO

Explanation:

^             #  Represents  begining of a line.
[a-z]         #  alphabatic  character.
.*            #  Any character 0 or more times.
[a-z]         #  alphabatic  character.
$             #  End of a line.
i             #  case-insensitive match.
g             #  global.
m             #  multiline

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08-14 22:16