JSFiddle - React, Tailwind, and code Playground
JavaScript
var nums = [4,3,1,0];
var missingNumber = function(nums) {
let sum = 0;
let expectedSum = nums.length;
for (var i = 0; i < nums.length; i++) {
sum += nums[i];
expectedSum += i;
}
return expectedSum - sum;
};
alert(missingNumber(nums));