Question

I have a string say:

 var currentLabel = "Uploading file... 0%"

This is the initial state when the upload starts and I need to update it as the operation runs. I need to take that 0 and replace it with a new number, however I can’t just get a substring since it will change to 2 digits eventually and the length will change…

If the length was constant I could do:

var newLabel = currentLabel.substring(0, currentLabel.length - 2) + percent + "%";

I’m guessing I need a regular expression or really any other way.

Answer 1

You could probably do it with a combination of indexOf and substring, but a regex does make it simpler:

newLabel = currentLabel.replace(/\d+$/, percent + "%");

There’s no other numbers in the string, right?

You could also just write the string again .. it would probably be even less expensive than the regex.