How to match numbers ranging from 1 to n with regex?

Question

I want to validate, using HTML pattern attribute (so i can get the notification), a numeric string that must only contain numbers ranging from 1 to 400 (I can allow 001).

I tried the following pattern but i'm missing a few many

^([1-3][0-9]{0,2}|400)$

Answer 1

Try this one ([1-9][0-9]{0,2}|400)$

[1-9][0-9]{0,2} matches any number between 1–999
|400 limit upto 400