Question

I have to validate for zero values in my text field, the length of text field is 4 chrs.
If the user enters 0 or 00 or 000 or 0000. this should fail.

presently i have written exp to validate values below 7500 which will also accept 0000.

please help me to tweek this to fail for 0 or 00 or 000 or 0000 values.

/^0*([0-9]{1,3}|[1-6][0-9]{3}|7[0-4][0-9]{2}|7500)$/

Thanks Punith

Answer 1

/^(?:[1-9]\d{0,2}|[1-6]\d{3}|7[0-4]\d{2}|7500)$/

Explanation:

^              # Start of string
(?:            # Either match...
 [1-9]\d{0,2}  # 1-999
|              # or
 [1-6]\d{3}    # 1000-6999
|              # or
 7[0-4]\d{2}   # 7000-7499
|              # or
 7500          # 7500
)              # End of alternation
$              # End of string

If you want to allow leading zeroes, then you can add 0* right after the ^. But then the length restriction to four digits is lost, of course.