What prevents my loop from correctly adding numbers in JavaScript?

Other Questions JavaScript
1

My JavaScript loop doesn’t sum values correctly and returns NaN. Check this updated example:

let totalX = 0;
let totalY = 0;
for (let k = 0; k < itemsList.length; k++) {
  let sampleData = itemsList[k].value.toString();
  let numX = parseFloat(sampleData.split(';')[1]);
  let numY = parseFloat(sampleData.split(';')[2]);
  totalX += numX;
  totalY += numY;
  console.log('totalX:', totalX);
  console.log('totalY:', totalY);
}
2

The loop may be running into issues if the values aren’t being parsed correctly as numbers. I’ve encountered similar problems where the input data sometimes includes unexpected characters or spaces, which leads parseFloat to return NaN. It might be useful to sanitize or trim the string before converting. Also, verify that every element in itemsList has a consistent format to avoid attempting to split a string that doesn’t match the expected pattern. If any of the results are NaN, the addition results will cascade and yield NaN for the total.

3

hey, try trmming the string cuz extra spaces can cause parseFloat to fail, leading to nan. also make sure that the data split returns the proper indexes so you’re not operating on undefined vals.

4

In my experience, encountering NaN in loops like this is usually due to unhandled data type issues in the input. It might help to check whether each split result exists, as missing elements in the semicolon separated string can cause parseFloat to operate on undefined. Additionally, consider using Number() as an alternative for conversion to see if that resolves the issue. Also, logging the intermediary string result before conversion proved particularly useful during debugging, allowing me to catch unexpected formatting errors and prevent the addition of invalid numbers.