javascript 和 c# 中的正则表达式问题

Question

I have to build some regex to validate some text. It must work in javascript and c#. I have to validate text in the following form:

text 1 text 2 text:2500.50 - valid

text 1:2500.50 - valid

text - valid

text:2500.505 - not valid (only 2 decimals are allowed)

name4: - not valid (if ':' exists then value must be provided)

name - valid

My best shot was:

^((([\S \r\t\f]+)\s*:\s*([0-9]+[.][0-9]{2})\s*)|[A-z0-9 \r\t\f\.\$\^\(\|\)\*\+\?\\\’\&\-\,]+\s*)+$

Another text i have to validate is:

1234 - valid

1234:3234.577843 - not valid(not valid (only 2 decimals are allowed))

1234:3234.54 - valid

1234: - not valid (if ':' exists then value must be provided)

123456:1234.45 - not valid(first group must have 4 digits).

For this text my best shot was: ^(([0-9]{4})\\s*:\\s*([0-9]+[.][0-9]{2})\\s*|[0-9]{4}\\s*)+$

I hope that you can help me.

Thanks

Answer 1

How about this regex ?

^(\d{4}|[\w ]*[A-Za-z][\w ]*)(:\d+(.\d{1,2})?)?$

Looks like it's giving the expected result, see this demo .