JavaScript: Check a credit card number format

JavaScript validation with regular expression: Exercise-2 with Solution

Write a JavaScript program to check a credit card number.

Here are some format of some well-known credit cards.

  • American Express :- Starting with 34 or 37, length 15 digits.
  • Visa :- Starting with 4, length 13 or 16 digits.
  • MasterCard :- Starting with 51 through 55, length 16 digits.
  • Discover :- Starting with 6011, length 16 digits or starting with 5, length 15 digits.
  • Diners Club :- Starting with 300 through 305, 36, or 38, length 14 digits.
  • JCB :- Starting with 2131 or 1800, length 15 digits or starting with 35, length 16 digits.

Sample Solution:

JavaScript Code:

function is_creditCard(str)
 regexp = /^(?:(4[0-9]{12}(?:[0-9]{3})?)|(5[1-5][0-9]{14})|(6(?:011|5[0-9]{2})[0-9]{12})|(3[47][0-9]{13})|(3(?:0[0-5]|[68][0-9])[0-9]{11})|((?:2131|1800|35[0-9]{3})[0-9]{11}))$/;
        if (regexp.test(str))
            return true;
            return false;






Flowchart: JavaScript- Check a credit card number format.

Live Demo:

See the Pen javascript-regexp-exercise-2 by w3resource (@w3resource) on CodePen.

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