👀 Views: 1754 💬 Answers: 1 📅 Created: 2025-06-19

javascript arrays error-handling JavaScript

I've hit a wall trying to I'm optimizing some code but I'm a bit lost with I've searched everywhere and can't find a clear answer... I'm working on a JavaScript function that calculates the ratio of each element in an array to the sum of all elements. However, I'm working with unexpected `NaN` (Not a Number) results when iterating through the array. Below is the code I've written: ```javascript function calculateRatios(arr) { const total = arr.reduce((acc, val) => acc + val, 0); return arr.map(num => total ? (num / total) : 0); } const myArray = [10, 20, 30, 'a']; // Intentionally adding a string to test behavior handling const ratios = calculateRatios(myArray); console.log(ratios); ``` When I run this code, I receive the following output: ``` [0.16666666666666666, 0.3333333333333333, 0.5, NaN] ``` I expected the function to handle the string `'a'` gracefully, but it seems to cause the calculation to unexpected result. I’ve tried adding a check to filter out non-numeric values before the calculation, like this: ```javascript function calculateRatios(arr) { const filteredArray = arr.filter(num => typeof num === 'number'); const total = filteredArray.reduce((acc, val) => acc + val, 0); return filteredArray.map(num => total ? (num / total) : 0); } ``` This change did not resolve the `NaN` scenario, and I still get the same results, particularly when other non-numeric values are present. Is there a better way to handle this situation? What am I missing? I’m using Node.js v16.13.0 and running this in a simple console environment. Any advice on best practices for ensuring all elements are numbers before performing calculations would be greatly appreciated. For context: I'm using Javascript on Windows 10. Any ideas what could be causing this? Hoping someone can shed some light on this. For reference, this is a production microservice. Has anyone dealt with something similar?