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Detailed explanation of using regular expressions to extract strings (with code)

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Release: 2018-03-29 17:52:47
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这次给大家带来使用正则表达式提取字符串详解,使用正则表达式提取字符串的注意事项有哪些,下面就是实战案例,一起来看一下。

在JS的正则零宽断言匹配中,只支持前瞻匹配,不支持后瞻。这就尴尬了,因为在业务当中,我们大多时候是知道了要目标数据的前后缀字符串,但是并不想连同前后缀一起获取。

为了模拟后瞻,我想,要不就用笨方法,先将前后缀字符串一同提取,然后再讲前后缀字符串一同replace为空字符串。于是就有了下面这个简单的方法,但确实很实用:

示例代码如下

// 提取固定字符之间的字符串
function getInnerString(source, prefix, postfix) {
 var regexp = new RegExp(encodeReg(prefix) + '.+' + encodeReg(postfix), 'gi');
 var matches = String(source).match(regexp);
 var formatedMatches = _.map(matches, value => {
  return value
   .replace(prefix, '')
   .replace(postfix, '');
 });
 return formatedMatches;
}
//转义影响正则的字符
function encodeReg(source) {
 return String(source).replace(/([.*+?^=!:${}()|[\]/\\])/g,'\\$1');
}
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使用:

var a = '让我们荡起双桨吧';
getInnerString(a, '让我们', '吧'); // ['双桨']
var b = '老总和不在办公室,有事请留言给李秘书';
getInnerString(b, '有事请留言给', ''); // ['李秘书']
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