正则表达式:如何匹配数字? [英] Regular expressions: how to match numbers?

问题描述

我想使用正则表达式来匹配这样的数字:

I want to use regular expressions to match numbers like these:

58158
60360
98198

其格式为ABCAB.

我使用下面的代码来匹配ABAB:

I use code below to match ABAB:

(([\d]){1,}([\d]){1,})\1{1,}

(例如5858)，但如何匹配ABCAB(58158)?

such as 5858 but how to match ABCAB(58158)?

推荐答案

对于格式为ABCAB的数字:

(\d)(\d)\d\1\2

这对A=B=C没有任何限制.对A!=B!=C使用否定前瞻:

This places no restriction on A=B=C. Use negative look-ahead for A!=B!=C:

(\d)(?!\1)(\d)(?!\1|\2)\d\1\2

没有边界匹配，因此58158将在36958158中匹配:

There is no boundary matching so 58158 will be matched in 36958158:

$num=36958158;
preg_match('/(\d)(?!\1)(\d)(?!\1|\2)\d\1\2/',$num,$match);
echo ">>> ".$match[0];

>>> 58158

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