JSFiddle - React, Tailwind, and code Playground

by saidulu401

JavaScript

//Find the missing number in an array of consecutive integers.
const detectiveArray = [1, 2, 3,4, 5, 6,8];

function findMissingNumber(arr){
  const max = Math.max(...arr)
  const expectedTotal = (max+1)*(max)/2
  const actualTotal = arr.reduce((a,b)=>a+b,0);
  return expectedTotal - actualTotal; 

}
console.log(findMissingNumber(detectiveArray))