Regex to not match a pattern in Javascript

Question

I need a reqular expression to not match this (/^[a-zA-Z][a-zA-Z0-9]+$/) pattern, where the string needs to start with alphabet followed by number and alphabet, with no special characters.

I tried with (/^??[a-zA-Z]?![a-zA-Z0-9]+$/) and not able to get appropriate answer.

Example:

P123454(Invalid)
PP1234(Invalid)
1245P(valid)
@#$124(valid) 

Thanks in advance.

Answer 1

This regex might be helpful:

/^[^a-zA-Z]+.*$/g

Your every valid input (from the question) should be a match.

Regex 101 Demo

Explanation:

• Does not allow string starting with a-zA-Z
• Everything after than is allowed (I'm not sure if this is a requirement)

Answer 2

^ means start with, So it should start with an alphabetic letter, then any number \d of alphabetic letters az with i case insensitive flag.

 const check = (str) => { return /^[^az].*/i.test(str) } console.log(check('P123454')) console.log(check('PP1234')) console.log(check('1245P')) console.log(check('@#$124'))