How to exclude certain words in regex in javascript?

Question

I have this regex to match username in my system: /[a-zA-Z]+([_-]?[0-9a-zA-Z]+)*$/. It starts with letters and allows numbers, _ and -. But I dont want the username includes some words like admin, facebook, official etc. How can I add these words to the regex? I want to use one regex to manage all the constraints.

Can you explain why this all has to be done in just one regex instead of doing it the easy way? — Andrew Morton, Mar 04 '18 at 00:31

Jeto · Answer 1 · 2018-03-04T01:20:14.853

1

Here's a possibility:

^((?!admin|facebook|official)[a-zA-Z])((?!admin|facebook|official|[-_]{2})[-_0-9a-zA-Z])*$

Demo

Edit: updated to make it more efficient.

edited Mar 04 '18 at 01:20

answered Mar 04 '18 at 00:37

Jeto

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Qwertiy · Answer 2 · 2018-03-04T00:52:25.870

1

/^(?=((?!(admin|facebook|official)).)+$)[a-z]+[_-]?[0-9a-z]+$/i

Check it:

input { width: 100%; box-sizing: border-box; outline: none; }
:valid { border: 1px solid green; }
:invalid { border: 1px solid red; }

<input pattern="^(?=((?!(admin|facebook|official)).)+$)[a-zA-Z]+[_-]?[0-9a-zA-Z]+$" autofocus>

edited Mar 04 '18 at 00:52

answered Mar 04 '18 at 00:47

Qwertiy

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How to exclude certain words in regex in javascript?

2 Answers2

Check it: