regular expression matching a 3 or 4 digit cvv of a credit card

Question

I really don\'t know regexp yet, but sooner or later I will read and learn. But for now I need a regular expression matching a 3 or 4 digit cvv of a credit card so I can valida

Answer 1

To match 3 or 4 digits, use the following regular expression:

/^[0-9]{3,4}$/

Explanation:

• ^: Start of string anchor
• [0-9]: Digit between 0 and 9 (you could also use \d here)
• {3,4}: A quantifier meaning between 3 and 4.
• $: End of string anchor