isCreditCard.js

isCreditCard.js

String.prototype.isCreditCard = function()
{
    //Credit - https://sites.google.com/site/abapexamples/javascript/luhn-validation
    var luhnArr = [[0,2,4,6,8,1,3,5,7,9],[0,1,2,3,4,5,6,7,8,9]], sum = 0;
    this.replace(/\D+/g,"").replace(/[\d]/g, function(c, p, o){
        sum += luhnArr[ (o.length-p)&1 ][ parseInt(c,10) ];
    });
    return (sum%10 === 0) && (sum > 0);
};