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JavaScript Build an Interactive Form

Neil Bircumshaw
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Neil Bircumshaw
Full Stack JavaScript Techdegree Student 14,597 Points
Posted by Neil Bircumshaw
.a{fill-rule:evenodd;}techdegree
Neil Bircumshaw
Full Stack JavaScript Techdegree Student 14,597 Points

input accepts only numbers

I'm trying to get it so that the input field only accepts numbers. I used a varible called "numbers" and said that if the input field was not equal to any numbers then it should display the error message, yet it doesn't. any tips?

HTML

  <div class="col-6 col">
            <label for="cc-num" id="ccn_label">Card Number:</label>
              <input id="cc-num" name="user_cc-num" type="text">
          </div>

JS

const ccn_num = document.getElementById("cc-num");

ccn_num.addEventListener("keyup", (e) => {

let numbers = /^[0-9]+$/;


if(credit_card_number.value.length === 0){
          e.preventDefault();
          ccn_message.textContent = "Please enter a credit card number in the field below.";
          ccn_message.style.color = "#cc0000";
          ccn_message.style.display = "block";
          ccn_message.className = "warning";
          ccn_message.style.fontSize = "1em";
          ccn_label.appendChild(ccn_message);
         }



        else if(credit_card_number.value.length < 13 || credit_card_number.value.length > 16 && !numbers.test(credit_card_number.value) ){
          e.preventDefault();
          ccn_message.textContent = "Please provide a valid credit card number. Thank you.";
          ccn_message.style.color = "#cc0000";
          ccn_message.style.display = "block";
          ccn_message.className = "warning";
          ccn_message.style.fontSize = "1em";
          ccn_label.appendChild(ccn_message);
         }

        else{ 
         ccn_message.style.display = "none";} 
    })

2 Answers

Steven Parker
Steven Parker
231,264 Points
Steven Parker
Steven Parker
231,264 Points

The non-identity operator ("!==") does not recognize regular expressions.

All it does is tell you if what you are comparing to is not another reference to the same regex object.

To use the regex to check your number, you'll need to apply a method that specifically uses a regex.

Steven Parker
Steven Parker
231,264 Points
Steven Parker
Steven Parker
231,264 Points

What about that "&&" logic — did you mean to perform that numbers test only if the length is greater than 16? Or should that "&&" be another "||"?