Optional regular expression match

Question

I have an string like 1566-02, where -02 is optional. If I use a regular expression like this

1566\s*-\s*\d{2}

it will always expect 2 numeric number with hyphen after 1566.

How I can make the -02 part optional, so that the IsMatch should be true for 1566 also?

For example - The value of IsMatch should be true if we pass the string as 1566 or 1566-02 or 1566-45 IsMatch value should be false for 1566-AC or 1566-

Please specify what language / platform you're using. Given that you mentioned IsMatch is this .NET? — p.s.w.g
– p.s.w.g, Commented Apr 9, 2014 at 21:47

p.s.w.g · Accepted Answer · 2014-04-09 21:51:25Z

3

Simply wrap it in a group and make it optional with the zero-or-one quantifier (?):

1566(\s*-\s*\d{2})?

To prohibit any other characters before or after the matched string, use start (^) and end ($) anchors:

^1566(\s*-\s*\d{2})?$

edited Apr 9, 2014 at 21:51

answered Apr 9, 2014 at 21:43

p.s.w.g

150k31 gold badges307 silver badges339 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

user3260341 Over a year ago

IsMatch value should be - true for 1566, 1566-23 but it should be false for 1566-AB. In this case everything becomes true

user3260341 Over a year ago

Thank you so much p.s.w.g - it meets my requirement

Collectives™ on Stack Overflow

Optional regular expression match

1 Answer 1

2 Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Related