有人可以告诉我如何阅读以下内容：/\\.(js)$/

Question

I'm trying to understand some webserver code I found online and the part right after the "else if" is the only part I don't understand. (I just started learning this stuff). Thanks

 var path = url.parse(req.url).pathname; // Managing the root route if (path == '/') { index = fs.readFile(__dirname+'/public/index.html', function(error,data) { //do stuff... }); // Managing the route for the javascript files } else if( /\\.(js)$/.test(path) ) { index = fs.readFile(__dirname+'/public'+path, function(error,data) { //do stuff... }); 

Answer 1

It allows you to test against regular expresions. Heres the MDN on how it works.

In your example, it's checking if the path ends in .js

Answer 2

Regular expressions produce non strict match against the string. Besides MSDN @SpeedOfRound mentioned about it would be useful to play with this service to get the better understanding on your exact case