Input field character sequence

Question

Input Field to follow and check for the following algorithm. Maximum 11 alpha-numeric characters:

1. 1st to 4th characters => Alphabetic characters- no numbers and special characters.

2. 5th characters => 0 (Just a single Zero)

3. 6th to 11th Characters => Alpha-numeric.

I think my question is quite simple, i want to enter 11 characters in an input field but first 4 characters should be as defined in point 1 and 5th character should be 0 and 6th characters to onward alphanumeric . input field should allow to enter characters as i defined , if some one want to enter 1 or other character at 5ht positions input field should not allow because 5ht position is for 0 and same expressions for other positions.

Answer 1

Looks like you have to use regex:

$('input').val().match(/^[a-z]{4}0[a-z0-9]{6}$/i);

1. ^ : Starts with
2. [a-z] : Allows Alphabetic characters
3. {4}: Matches 4 preceding characters
4. 0 : Matches 0
5. [a-z0-9]: Matches any characters from a-z and 0-9 in any sequence
6. $: End of string
7. i: Case insensitive match