[RESOLVED] Validate empty string in regular expression

[bodylojohn]

Hello,

I have a string field where the user only can enter NULL or the nummeric value 1-199

I know

^([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-9][0-9]|3[0-9][0-9]|4[0-9][0-9]|5[0-9][0-9]|6[0-9][0-9]|7[0-9][0-9]|8[0-9][0-9]|9[0-9][0-9])$

Checks for the value 0 to 199 but not null.


How can I change the formula so When Null or 1 to 199 is entered results in a match?

[ComputerJy]

^([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-9][0-9]|3[0-9][0-9]|4[0-9][0-9]|5[0-9][0-9]|6[0-9][0-9]|7[0-9][0-9]|8[0-9][0-9]|9[0-9][0-9])?$

[bodylojohn]

That's it..

Thank you very much!!!!!

[bodylojohn]

One small question?

What when I want to match for empty spaces?

[ComputerJy]

\s is the regex symbol for white space (space, v-tab... etc) You can check out regex lib for samples and details