How do I use a regular expression to match a fixed-length number with a hyphen in the middle?

Question

I am new to regular expressions and wanted to know how to write a regular expression that does the following:

Validates a string like 123-0123456789. Only numeric values and a hyphen should be allowed. Also, verify that there are 3 numeric chars before the hyphen and 10 chars after the hyphen.

Answer 1

The given answers won't work for strings with more digits (like '012-0123456789876'), so you need:

str.match(/^\d{3}-\d{10}$/) != null;

or

/^\d{3}-\d{10}$/.test(str);

Answer 2

Try this:

^\d{3}-\d{10}$

This says: Accept only 3 digits, then a hyphen, then only 10 digits

Answer 3

Sure, this should work:

var valid = (str.match(/^\d{3}-\d{10}$/) != null);

Example:

> s = "102-1919103933";
"102-1919103933"
> var valid = s.match(/\d{3}-\d{10}/) != null;
> valid
true
> s = "28566945";
"28566945"
> var valid = s.match(/\d{3}-\d{10}/) != null;
> valid
false