Regular expression starting with letter 'c' or 'r'

Question

I want to create a regular expression that will check if this input starts with letters c or r then any amount of letters or numbers after that is fine here is my code so far:

/^c[a-zA-Z]*/

How would I change this allow either c or r or in capitals C or R at the beginning?

`[crCR]` instead of `c`? See https://stackoverflow.com/q/4736/1225328. — sp00m, Jul 18 '18 at 11:50
I get this error: Validator `^r/i[a-zA-Z]*/` is not defined! — S.Rafiq, Jul 18 '18 at 11:51

Ankit Agarwal · Accepted Answer · 2018-07-18T12:02:13.943

2

You can use the regex /^[cr][0-9a-z]*$/i for case insensitive match:

var regex = /^[cr][0-9a-z]*$/i;
console.log(regex.test('cat'));
console.log(regex.test('dog'));
console.log(regex.test('Race'));
console.log(regex.test('rat'));
console.log(regex.test('c'));

edited Jul 18 '18 at 12:02

answered Jul 18 '18 at 11:57

Ankit Agarwal

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when i try inputting i get: Invalid regular expression: /^(/: Unterminated group – S.Rafiq Jul 18 '18 at 12:03
@S.Rafiq glad to help. – Ankit Agarwal Jul 18 '18 at 12:08

score 0 · Answer 2 · edited Jul 18 '18 at 13:41

0

This should work ^([cC]|[rR])\w*$

I created an online playground for you regexr.com/3skji

edited Jul 18 '18 at 13:41

Johannes

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answered Jul 18 '18 at 11:52

Appeiron

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`\w` matches "\_", so it will match "c\_\_\_". – ASDFGerte Jul 18 '18 at 11:57
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Posting a link to an answer isn't the same as posting an answer. – Tom Fenech Jul 18 '18 at 12:01

Regular expression starting with letter 'c' or 'r'

2 Answers2