javascript 将单词（字符串）数组转换为正则表达式并使用它来获取字符串的匹配项
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convert array of words (strings) to regex and use it to get matches on a string
提问by kuus
What is the most concise and efficient way to translate an array of strings in a regex and then use the regex multiple times on different strings to get the result matches and then iterate over them? Now I'm using the following:
翻译正则表达式中的字符串数组，然后在不同的字符串上多次使用正则表达式以获得结果匹配，然后迭代它们的最简洁和有效的方法是什么？现在我正在使用以下内容：
var myArray = ['peaches', 'bananas', 'papaya', 'supercity'];
var myString = 'I want some papaya and some peaches';
var regexFromMyArray = new RegExp(myArray.toString().replace(/,/g, '|'), 'gi');
var matches = myString.match(regexFromMyArray) || [];
if (matches.length) {
for (var i = 0, l = matches.length; i < l; i++) {
console.log('Found: ' + matches[i]);
}
}
performance is important here, so plain javascript please.
性能在这里很重要，所以请使用简单的 javascript。
回答by Amit Joki
Just join with pipeline, using Array.join
只需加入管道，使用 Array.join
var regexFromMyArray = new RegExp(myArray.join("|"), 'gi');
and just do this as ifcondition is just redundant.
并且只是这样做，因为if条件只是多余的。
for(var i = 0; i < matches.length; i++)
console.log("Found:", matches[i]);
- A single method is being used instead of initial 3. (
toStringinternally callsjoin(",")) andreplacefunction is also not used. - We have removed an unnecessary if-condition. So that's pretty quick.
- 正在使用单个方法而不是初始 3。（
toString内部调用join(",")）和replace函数也未使用。 - 我们删除了一个不必要的 if 条件。所以这很快。
And since you talk about regexes, I'd like to say that
既然你谈论正则表达式，我想说
- A single regex initialization isn't going to cost you much.
- If your objective is really to match the words in the array, then just go with
String.indexOf, which is a non-regex form of solving the same.
- 单个正则表达式初始化不会花费太多。
- 如果您的目标真的是匹配数组中的单词，那么只需使用
String.indexOf，这是解决相同问题的非正则表达式形式。
