Regex Expression on 16-digit number

Question

I am stuck on this regex problem.

A 16-digit credit card number, with the first digit being a 5 and the second digit being a 1, 2, 3, 4, or 5 (the rest of the digits can be anything).

so far I have ^4[1,5]\d{14} and I know I'm missing a lot of things but I dont know what I'm missing..

please help and thanks!

Check for a solution at [Regex credit card number tests](https://stackoverflow.com/questions/9315647/regex-credit-card-number-tests). — Wiktor Stribiżew, Jun 04 '18 at 20:42
In regex `1,5` doesn't indicate a range but does `1-5`. You need `^4[1-5]\d{14}$` — revo, Jun 04 '18 at 20:42

score 2 · Answer 1 · answered Jun 04 '18 at 20:41

Look at the start of your regex:

^4[1,5]

That says that the number must start with 4 (not 5), and that the second character must be 1, a comma, or 5.

You want this instead (followed by the rest, of course):

^5[1-5]

Note the use of - rather than , to indicate a range of characters.

Yassin Hajaj · Answer 2 · 2018-06-05T03:28:01.817

1

The full regex you're looking for is the following

^5[1-5]\d{14}$

Demo

Your error lays in the fact that you used 1,5 as a range but this will just match 1 , or 5 as characters. To use a range, the - is needed between the enclosings

edited Jun 05 '18 at 03:28

answered Jun 04 '18 at 21:04

Yassin Hajaj

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Regex Expression on 16-digit number

2 Answers2