Question

As the title states: Can any one help me figure out how to write a JavaScript regex expression that matches a string that end in “.js” but fails when given a string that ends in “-min.js”.

Examples:

hello.js -> match

hellomin.js -> match

hello-min.js -> no match

hello-min-hello.js -> match

Thanks!

Answer 1

Use negative lookahead:

(?!-min)[\w-]{4}\.js$

Update

This will also work for less than 4 characters before the .js:

(?:(?!-min)[\w-]{4}|^[\w-]{1,3})\.js$