isJCB

isJCB :: a → Boolean

Reports whether the received value is a valid credit card number and is a JCB card

import isJCB from 'deep-waters/credit-cards/isJCB';

isJCB(3528701379615495); // JCB → true

isJCB(347190259623701); // American Express → false
isJCB(4286124395547263); // VISA → false
isJCB(38716394960899); // Diners Club → false
isJCB(6011583945260254); // Discover → false
isJCB('6011-5839-4526-0254'); // Credit card format → false
isJCB("foo"); // → false
isJCB(undefined); // → false

Please note, isJCB assumes the receiving value is a number or a string without the usual dashes. It only evaluates the credit card number, not its format.