Regular expression
/^(?:\d[ -]*?){13,19}$/Pattern breakdown
| Part | Meaning |
|---|---|
Anchor or context | Use anchors when you need whole-string validation. |
Main token | The core token sequence describes the accepted text shape. |
Character class | Character classes limit which characters are valid. |
Quantifier | Quantifiers control how many characters or groups are accepted. |
Flags | Use language-specific flags such as i, m, or u only when needed. |
Should match
4111 1111 1111 11114111111111111111
Should not match
4111-abcnot matching sample4111 1111 1111 1111 invalid4111-abc4111 1111 1111 1111
Test cases
| Input | Expected | Why it matters |
|---|---|---|
4111 1111 1111 1111 | Match | Representative valid input for this pattern. |
4111111111111111 | Match | Representative valid input for this pattern. |
4111-abc | No match | Common invalid or boundary input. |
(empty string) | No match | Common invalid or boundary input. |
not matching sample | No match | Common invalid or boundary input. |
4111 1111 1111 1111 invalid | No match | Common invalid or boundary input. |
4111-abc4111 1111 1111 1111 | No match | Common invalid or boundary input. |
JavaScript
const re = /^(?:\d[ -]*?){13,19}$/;
re.test(input);Python
import re
bool(re.search(r"^(?:\d[ -]*?){13,19}$", text))PHP
$ok = preg_match('/^(?:\d[ -]*?){13,19}$/', $value) === 1;Java
Pattern pattern = Pattern.compile("^(?:\\d[ -]*?){13,19}$");
pattern.matcher(value).find();Go
re := regexp.MustCompile(`^(?:\d[ -]*?){13,19}$`)
ok := re.MatchString(value)Notes and production use
Credit Card Number Shape regex is useful as a practical starting point. Test it against your real input, avoid using it as the only security control, and prefer a parser when the format has complex grammar.
Performance tip: avoid running complex regular expressions repeatedly on very large untrusted strings without limits. Prefer anchored validation patterns, cap input length before matching, and use a parser when the target format has nested grammar.