Pattern: For-in loop over array
Issue: -
Disallows iterating over an array with a for-in loop.
A for-in loop (for (var k in o)) iterates over the properties of an Object.
While it is legal to use for-in loops with array types, it is not common. for-in will iterate over the indices of the array as strings, omitting any “holes” in the array.
More common is to use for-of, which iterates over the values of an array. If you want to iterate over the indices, alternatives include:
array.forEach((value, index) => { … });
for (const [index, value] of array.entries()) { … }
for (let i = 0; i < array.length; i++) { … }