isCreditCard

The isCreditCard function checks if a string matches the format of a valid credit card number (Visa, MasterCard, American Express, Discover, JCB, Diners Club, among others).

Syntax

isCreditCard(value)

Parameters

Parameter	Type	Description
value	string	The string to be checked.

Return

Type	Description
boolean	Returns true if the string matches the format of a valid credit card, otherwise returns false.

Examples

isCreditCard('4111111111111111'); // true (Visa)
isCreditCard('5500000000000004'); // true (MasterCard)
isCreditCard('340000000000009');  // true (American Express)
isCreditCard('1234567890123456'); // false
isCreditCard('abcd');             // false
isCreditCard('');                 // false

Notes

• Throws a TypeError if the provided value is not a string.
• Only validates the format; does not check if the card is active or authorized.

References

• MDN: String.prototype.test()
• Wikipedia: Credit card number