JSFiddle - React, Tailwind, and code Playground

by atesgoral

JavaScript

/*** Prep ***/
var numbers = [];

// Get a list of numbers 1-100
for (var i = 1; i <= 100; i++) {
    numbers.push(i);
}

// Random shuffle
numbers.sort(function () {
    return 0.5 - Math.random();
});

// Remove last
var missing = numbers.pop();

/*** Solution ***/
for (var i = 0, answer = 7; i < 99; i++) answer ^= i ^ numbers[i];

document.write(answer === missing);