views:

123

answers:

3

Hi Guys,

I'm trying to create a regex that accept: An empty string, a single integer or multiple integers separated by a comma but can have no starting and ending comma.

I managed to find this, but I cannot undertsand how to remove the digit limit

^\d{1,10}([,]\d{10})*$
+3  A: 

{1,10} and {10} are ranges. You can replace them with + for infinite-positive. Eg.:

^\d+([,]\d+)*$
troelskn
Methinks that you can also omit the square brackets around the comma.
Richard Barrell
Methinks you're right.
troelskn
+5  A: 

The thing you posted still requires at least 1 integer, so it won't match an empty string:

Here is what you need:

^(\d+(,\d+)*)?$

Explaination:

  1. put the entire thing in parenthesis and end with a '?' so as to match the empty string.
  2. Always start with an integer, so '\d+'. That is 1 or more digit characters ('0'-'9')
  3. Then make a set of parenthesis which contains ',\d+' and put an asterisk after it.
    3a. The inside means start with a ',' then an integer. 3b. The asterisk means repeat everything inside the parenthesis 0 or more times.

Hench the whole thing is either an empty string or start with an integer then repeat zero or more times a string which starts with a comma and ends with an integer

tster
All work but i had to choose one, and first come first served took it, thanks :)
Metju
@Metzu, Be aware that the first one doesn't match an empty string...
tster
+1  A: 

^(\d+(,\d+)*)?$

Algirdas
Thanks for that :)
Metju