I am trying to write some form validation, I need one of the inputs to be 1-9999. I know nothing about regular expressions ( never used them before) and here is my first attempt
This Regex should not match numbers that start with 0 a part from 0
Regex: /^(?!(0\d))\d{1,4}$/
Regex (Exclude Zero): /^(?!(0))\d{1,4}$/
Test: https://regex101.com/r/zfCKel/2
Try the below regex,
^(?:[1-9][0-9]{3}|[1-9][0-9]{2}|[1-9][0-9]|[1-9])$
DEMO
Try using this
^([1-9]|[1-9][0-9]|[1-9][0-9][0-9]|[1-9][0-9][0-9][0-9])$
This doesn't exclude zero, but /^\d{1,4}$/
should do the trick.