Question

var cards = new Array();

 cards [0] = {name: "VISA", length: "13,16", prefixes: "4", checkdigit: true};
 cards [1] = {name: "VISA_DELTA/ELECTRON", length: "16", prefixes: "417500,4844,4508,4026,4917,4913", checkdigit: true};
 cards [2] = {name: "MC", length: "16", prefixes: "51,52,53,54,55", checkdigit: true};

然后是我的职能：

function CardTypes()
{
for (var i=0; i<cards.length; i++) {
if cards.name.Validate(PaymentForm.CardNumber.value)<!--pretty sure this is wrong-->
cardname = cards[i].getCardType();
}
if (cardname.length > 0) {
alert("This looks like a " + cardname + " .");
};
};

提交表单时，它调用Validate函数，该函数又调用包括CardTypes（）在内的所有其他函数。我希望能够通过卡前缀确定卡类型，即4 =签证。我很确定我完全弄乱了CardTypes（）函数。任何帮助，将不胜感激。我的表单ID是PaymentForm。

Answer 1

PaymentForm.CardNumber.value设置为什么？这是卡的整数吗？

var cardNumber = PaymentForm.CardNumber.value;

如果这是正确的，那么你会想要读取所有前缀，例如

   for (var i=0; i<cards.length; i++) {

      var prefixes= cards[i].prefixes;
      var prefixArray = prefixes.split(",");

         for(var j=0; j < prefixArray.length; j++) {

            if(cardNumber.startsWith(prefixArray[j])) {
               alert("Card Type is " + cards[i].name);
            }

          }  
   }

//将此方法添加到String

String.prototype.startsWith = function(str){
    return (this.indexOf(str) === 0);
}

JSFiddle：http://jsfiddle.net/KDTPX/

Answer 2

function CardTypes()
{
    var givenValue = PaymentForm.CardNumber.value;
    for (var i = 0; i < cards.length; i++) {
        var cardPrefixes = cards[i].prefixes.split(',');
        var leave = false;
        for (var j = 0; j < cardPrefixes.length; j++) {
            if (givenValue.indexOf(cardPrefixes[j]) === 0) {
                return cards[i].name;
            }
        }
    }
}

这应该有用。

确定与卡前缀相关的卡

2 个答案: