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Doubts about regular expressions w and d regular expression numbers python regular expression grep regular expression

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Release： 2016-07-29 08:49:53

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<code><span><span><?php</span><span>$string</span>=<span>'April15,2003'</span>;
<span>$pattern</span>=<span>'/(\w+)(\d+),(\d+)/i'</span>;
<span>$replacement</span>=<span>'${1},${3}'</span>;
<span>echo</span> preg_replace(<span>$pattern</span>,<span>$replacement</span>,<span>$string</span>);
<span>?></span></span></code>

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这个表达式的结果为April1,2003
原因：(\w+)能够完整匹配April15，但是因为在(\w+)后面有(\d+)，为了能够匹配定义的规则，(\w+)会匹配April1，(\d+)会匹配5
可以换个表达式避免出现这种情况如：
$pattern=’/([a-z])(\d+),(\d+)/i’;

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').addClass('pre-numbering').hide(); $(this).addClass('has-numbering').parent().append($numbering); for (i = 1; i ').text(i)); }; $numbering.fadeIn(1700); }); });

以上就介绍了正则表达式\w和\d的疑惑，包括了正则表达式方面的内容，希望对PHP教程有兴趣的朋友有所帮助。

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