regex 1-9999 for form validation

Question

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

Answer 1

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