Sabrina Markon - Algorithms - We add a new integer to an existing array of integers, sort it using compare, then return the index of the first occurrence of the new element.

algorithm-add-element-to-array-then-sort-and-return-first-index-of-the-value-of-the-added-element.txt

Sabrina: Notice how sort() includes a compare function. Since sort sorts by alphabetical order, sorting numbers tends to be WRONG.
The string "25" for example is GREATER THAN the string "100". So we compare with function(a,b) { return a-b; } to sort NUMBERS in
ASCENDING ORDER. (for descending order use return b-a instead).

Return the lowest index at which a value (second argument) should be inserted into an array (first argument) once it has been sorted. 
The returned value should be a number.

For example, getIndexToIns([1,2,3,4], 1.5) should return 1 because it is greater than 1 (index 0), but less than 2 (index 1).

Likewise, getIndexToIns([20,3,5], 19) should return 2 because once the array has been sorted it will look like [3,5,20] and
19 is less than 20 (index 2) and greater than 5 (index 1).

function getIndexToIns(arr, num) {
  // Find my place in this sorted array.
  arr.push(num);
  arr.sort(function(a,b) { return a-b; });
  var position = arr.indexOf(num);
  
  return position;
}

getIndexToIns([40, 60], 50);

TESTS:
getIndexToIns([10, 20, 30, 40, 50], 35) should return 3.
getIndexToIns([10, 20, 30, 40, 50], 30) should return 2.
getIndexToIns([40, 60], 50) should return 1.
getIndexToIns([3, 10, 5], 3) should return 0.
getIndexToIns([5, 3, 20, 3], 5) should return 2.
getIndexToIns([2, 20, 10], 19) should return 2.
getIndexToIns([2, 5, 10], 15) should return 3.