script.js

[Riya54671]

Duplicate Event Handlers
The #card-holder event handler is defined twice for keyup and change events. This redundancy leads to duplicate functionality.
Fix: Remove one of the duplicated event handlers to avoid unnecessary execution
2. Use of next() Without Checking for Element Existence
In the .input-cart-number handlers, the code uses $t.next().focus(); without checking if the next() element exists.
Issue: If .next() returns undefined (i.e., no element exists after the last input field), calling focus() will result in an error.
Fix: Add a check before calling focus().
Misuse of setTimeout()
There’s a call to setTimeout() without a proper function definition
Issue: The setTimeout() is incomplete, making it redundant or incorrect.
Fix: If this is supposed to delay execution, include proper functionality within the function or remove it if unnecessary.
Inefficient Card Number Concatenation
Issue: The card_number concatenation is unnecessary and inefficient if there are many fields.
Fix: Use map() and join() to build the card_number more efficiently.
5. Month Value Handling
The code for extracting the month uses an unnecessary .index() call
Issue: You can directly retrieve the value of the selected option without needing to calculate the index.
Fix: Use val() directly for the month.
6 Inconsistent Event Handlers for the Card Type Detection
The getCreditCardType() function is commented out and unused in the final code.
Fix: If detecting the card type based on the number is needed, uncomment and integrate the function. Otherwise, remove it.
7. Potential Accessibility and Usability Issues
The code relies heavily on the use of .keyup, which might not cover all possible input scenarios (e.g., autofill).
Fix: Consider using both input and change events instead of just keyup.
8 Magic Numbers for CCV Length
The maxlength attribute for the #card-ccv is hardcoded to 3, but some card types (e.g., Amex) have a 4-digit CVV.
Fix: Implement card type detection logic and adjust the CVV length accordingly.
9. Potential Global Variable Issues
$t is used as a variable but is not declared with var, let, or const. This can cause it to become a global variable.
Fix: Declare $t using let or const.