Solving the Problem with Arrays When Used with a Function скачать в хорошем качестве

Solving the Problem with Arrays When Used with a Function

Discover how to properly manage arrays in JavaScript functions to avoid unintended mutations and ensure accurate results. --- This video is based on the question https://stackoverflow.com/q/69698443/ asked by the user 'omarfarah' ( https://stackoverflow.com/u/16774233/ ) and on the answer https://stackoverflow.com/a/69698990/ provided by the user 'aerial' ( https://stackoverflow.com/u/17175441/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Problem with Arrays when being used with a function Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Understanding the Problem: Managing Arrays in JavaScript Functions Are you facing issues with arrays when using functions in JavaScript? If your code seems to work for individual cases but fails to produce the expected output for larger datasets, you may be running into a common pitfall related to how arrays are manipulated inside functions. Today, we're going to explore a specific case: how a function that validates credit card numbers can inadvertently alter the original arrays. In the provided code, we have a function called validateCred() designed to check an array of credit card numbers for validity. The issue arises when this function is used inside another function, findInvalidCards(), which processes an array of credit card arrays. The results seem incorrect because the original arrays are being modified unexpectedly. The Core of the Issue The problem stems from this line within the validateCred() function: [[See Video to Reveal this Text or Code Snippet]] By directly manipulating the elements of the arr parameter, we are unintentionally changing the original credit card arrays. This leads to unexpected results when we try to validate those same arrays again later on. A Clearer Solution: Avoiding Direct Mutation To resolve the issue, we can adopt a safer approach by working with a copy of the array element rather than modifying it directly. Here’s how you can implement that change: Step-by-Step Code Update Declare a variable to store the current element value: [[See Video to Reveal this Text or Code Snippet]] Assign the value of each array element to this variable before any operations: [[See Video to Reveal this Text or Code Snippet]] Perform the necessary calculations on currentNumber instead of directly modifying arr[i]: [[See Video to Reveal this Text or Code Snippet]] Accumulate the sum with currentNumber: [[See Video to Reveal this Text or Code Snippet]] The Updated validateCred() Function Here’s how your updated function should look based on the above steps: [[See Video to Reveal this Text or Code Snippet]] Conclusion: Clean Code Practices By ensuring that we do not directly mutate the original arrays, we can maintain the integrity of our data and ensure accurate results. This approach is a good coding practice that applies not just to this specific case with credit card validation, but throughout JavaScript programming. If you stick to using variables for mutable operations instead of changing the original data, you will save yourself plenty of headaches in debugging and will create more reliable and maintainable code. Happy coding!