Arrays - Find missing numbers in a Sequence

Question

I\'m trying to find an easy way to loop (iterate) over an array to find all the missing numbers in a sequence, the array will look a bit like the one below.

var nu

Answer 1

Assuming that there are no duplicates

let numberArray = [];

for (let i = 1; i <= 100; i++) {
  numberArray.push(i);
}
let deletedArray = numberArray.splice(30, 1);
let sortedArray = numberArray.sort((a, b) => a - b);
let array = sortedArray;

function findMissingNumber(arr, sizeOfArray) {
  total = (sizeOfArray * (sizeOfArray + 1)) / 2;
  console.log(total);
  for (i = 0; i < arr.length; i++) {
    total -= arr[i];
  }
  return total;
}

console.log(findMissingNumber(array, 100));