Use Case:

working with arrays

First Principles:

using for loop

const getIndexToIns = (arr, num) => {
  const cloneArr = arr.sort((a, b) => a - b);
  let retNum = 0;
  if (cloneArr.includes(num)) return cloneArr.indexOf(num);
  if (num > cloneArr[cloneArr.length - 1]) return cloneArr.length;
  for (let i = 0; i < cloneArr.length; i++) {
    if (num > cloneArr[i - 1] && num < cloneArr[i]) {
      retNum = i;
    }
  }

  return retNum;
}

using .filter() method

const getIndexToIns = (arr, num) => {
  // filter all values that are not greater than num and get length
 return arr.filter((val) => num > val).length;
}

Things that I did not consider

Initially, I did not consider adding num to the array and then sorting to find index. In retrospect, this seems like the most natural answer.

I had initally thought about how to reduce the number of elements after sorting, and I could have approached the problem with less complexity, since I initially conceived of something fairly complicated.

Why I had to learn this

I am currently working through JavaScript Data Structures and Algorithms certification