[英]Why isn't my credit card validation working?
我正在向表單添加信用卡驗證。
如果用戶單擊注冊按鈕,但沒有有效的信用卡號,則將標記錯誤,標簽將變為紅色。
它還確保CVV字段和郵政編碼字段不為空。
現在,如果我在字段為空的情況下單擊按鈕,則會收到所需的錯誤。
如果然后我填寫郵政編碼和CSV,然后再次單擊注冊,則錯誤將被消除。
但是,什么也不會刪除CC號標志。
為什么會這樣,我該如何解決?
代碼如下,謝謝:
// Form validation. Display error messages and don't let the user submit the form if any of these validation errors exist:
document.querySelector("button").addEventListener("click", function(e) {
//check there's a valid credit card number
var ccNum = document.getElementById("cc-num");
var ccNumLbl = document.getElementById("cc-numLbl");
// takes the form field value and returns true on valid number
//algorithm found here: https://gist.github.com/DiegoSalazar/4075533
function valid_credit_card(value) {
// accept only digits, dashes or spaces
if (/[^0-9-\s]+/.test(value)) return false;
// The Luhn Algorithm. It's so pretty.
var nCheck = 0, nDigit = 0, bEven = false;
value = value.replace(/\D/g, "");
for (var n = value.length - 1; n >= 0; n--) {
var cDigit = value.charAt(n),
nDigit = parseInt(cDigit, 10);
if (bEven) {
if ((nDigit *= 2) > 9) nDigit -= 9;
}
nCheck += nDigit;
bEven = !bEven;
}
return (nCheck % 10) == 0;
}
if(!valid_credit_card(ccNum.input)) {
ccNumLbl.style.color = "red";
e.preventDefault();
} else {
ccNumLbl.style.color = "black";
}
//check there's a zip code
var zip = document.getElementById("zip");
var zipLbl = document.getElementById("zipLbl");
if(zip.value.length === 0) {
zipLbl.style.color = "red";
e.preventDefault();
} else {
zipLbl.style.color = "black";
}
//check there's a cvv
var cvv = document.getElementById("cvv");
var cvvLbl = document.getElementById("cvvLbl");
if(cvv.value.length === 0) {
cvvLbl.style.color = "red";
e.preventDefault();
} else {
cvvLbl.style.color = "black";
}
});
和html:
<div id="credit-card" class="credit-card">
<div class="col-6 col">
<label id="cc-numLbl" for="cc-num">Card Number:</label>
<input id="cc-num" name="user_cc-num" type="text">
</div>
<div class="col-3 col">
<label for="zip" id="zipLbl">Zip Code:</label>
<input id="zip" name="user_zip" type="text">
</div>
<div class="col-3 col">
<label id="cvvLbl" for="cvv">CVV:</label>
<input id="cvv" name="user_cvv" type="text">
</div>
<label>Expiration Date:</label>
<select id="exp-month" name="user_exp-month">
<option value="1">1 - January</option>
<option value="2">2 - February</option>
<option value="3">3 - March</option>
<option value="4">4 - April</option>
<option value="5">5 - May</option>
<option value="6">6 - June</option>
<option value="7">7 - July</option>
<option value="8">8 - August</option>
<option value="9">9 - September</option>
<option value="10">10 - October</option>
<option value="11">11 - November</option>
<option value="12">12 - December</option>
</select>
<select id="exp-year" name="user_exp-year">
<option value="2016">2016</option>
<option value="2017">2017</option>
<option value="2018">2018</option>
<option value="2019">2019</option>
<option value="2020">2020</option>
</select>
</div>
<button type="submit">Register</button>
似乎您正在嘗試獲取文本輸入對象而不是其值。 您需要將ccNum
變量分配更改為
var ccNum = document.getElementById('cc-num').value;
同樣, querySelector
函數在您的代碼中失敗了,為此我將<input type="button"...>
聲明為(向其添加了類屬性),
<input type="button" class="button" id="myBtn" value="Validate" />
並將document.querySelector(...)
函數更改為
document.querySelector(".button").addEventListener("click", function(e) {
工作演示 : https : //jsfiddle.net/nmvk9ks7/1/
希望這可以幫助!
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