Regex | validation error

Question

I'm trying to validate a USA mobile number, since I'm using pre-built javascript validation library I just replaced this regex validation with the previous one which comes with the validation library.

previous validation regex:

"telephone":{
"regex":"/^[0-9\-\(\)\ ]{10,10}$/",
"alertText":"* Invalid phone number"},

This works like 2126661234 but not in USA standard.

After I changed:

"telephone":{
"regex":"/^[2-9]\d{2}-\d{3}-\d{4}$/",
"alertText":"* Invalid phone number"}, 

Now every entry I get an error even if I enter 212-666-1234 I really don't know what is the wrong, so I'm expecting some help.

Answer 1

Looks like the original regex escapes the - sign, like this: \-.

I don't see you doing that in your second example.

Answer 2

You need to escape the backslashes

"telephone":{
"regex":"/^[2-9]\\d{2}-\\d{3}-\\d{4}$/",
"alertText":"* Invalid phone number"}, 

/^[2-9]\d{2}-\d{3}-\d{4}$/ works only in regex literals as in

var r = /^[2-9]\d{2}-\d{3}-\d{4}$/;

When you are using strings to initialize regex, you should escape the backslashes

var r = new RegExp("^[2-9]\\d{2}-\\d{3}-\\d{4}$");