ecmascript 6 - Find and remove all non numbers from array in JavaScript w/out JQuery

Question

There was a question on a coding interview and I felt like it would be easy by using isNaN within a for loop and then splicing that index. Come to find out it didn't work and I haven't found a single thing online that shows how to do it. This is without jQuery and just strictly ES6 javascript. Say you are given an array..... arr = [2, "a", 4, "b", 3, 5, "c"]. Without making a new array, modify the existing array to contain only numbers. How would you go about removing all non-numbers from the array? I have not found one solution online that does not use jQuery.

Answer 1

Array.splice is useful here. I'm sure this solution can be optimized.

array.forEach((item, index) => typeof item !== 'number' && array.splice(index, 1));