如何使用正则表达式匹配没有扩展名的文件名单词？

Question

I want to match the words in a filename without characters like underscores (_) and the file extension. For example, if i have the files image_one.jpg and image_two.png then how can I match only image one and image two ? I am not sure how to exclude the underscore and the.extension.

So far, I have \w*_\w* but it matches the file name including the underscore ie image_one and image_two

Answer 1

Your pattern \w*_\w* could possibly also match a single _ as the word chars are optional.

As \w also matches an underscore, you can exclude it from \w by using a negated character class. [^\W_] .

To get both values, you could use 2 capturing groups and if the pattern must only match at the end of the string you can add $ at the end.

([^\W_]+)_([^\W_]+)\.\w+

Explanation

• ([^\W_]+) Capture group 1, match 1+ times a word char except _
• _ Match the underscore
• ([^\W_]+) Capture group 2, same as for group 1
• \.\w+ Match a . and 1+ word chars (or \.(?:jpg|png) to be more precise)

See a Regex demo

 const regex = /([^\W_]+)_([^\W_]+)\.\w+/; [ "image_one.jpg", "image_two.png" ].forEach(s => console.log(s.match(regex).slice(1)));