Question

The following regular expression isn’t working for international phone numbers that can allow up to 15 digits:

^[a-zA-Z0-9-().\s]{10,15}$

What needs to be adjusted?

Answer 1

Try adding a backslash:

var unrealisticPhoneNumberRegex = /^[a-zA-Z0-9\-().\s]{10,15}$/;

Now it’s still not very useful because you allow an arbitrary number of punctuation characters too. Really, validating a phone number like this — especially if you want it to really work for all possible international phone numbers — is probably a hopeless task. I suggest you go with what @BalusC suggests.