js-rock-paper-scissors/main.js

const ROCK = "rock";
const PAPER = "paper";
const SCISSORS = "scissors";
let ties = 0;

function getComputerChoice () {
    let x = Math.floor(Math.random() * 3);
    if (x === 1) {
        return ROCK;
    }
    else if (x === 2) {
        return PAPER;
    }
    else {
        return SCISSORS;
    }
}

function playRound () {
    const computerSelection = getComputerChoice();
    const playerSelection = (prompt("Rock, Paper or Scissors?")).toLowerCase();
    if (playerSelection === computerSelection) {
        alert("It's a tie!");
        ties++;
    }
    else if (playerSelection === ROCK) {
        if (computerSelection === PAPER) {
            alert("You Lose! Paper beats Rock!");
            return 0;
        }
        else {
            alert("You Win! Rock beats Scissors!");
            return 1;
        }
    }
    else if (playerSelection === PAPER) {
        if (computerSelection === ROCK) {
            alert("You Win! Paper beats Rock!");
            return 1;
        }
        else {
            alert("You Lose! Scissors beat Paper!");
            return 0;
        }
    }
    else if (playerSelection === SCISSORS) {
        if (computerSelection === ROCK) {
            alert("You Lose! Rock beats Scissors!");
            return 0;
        }
        else {
            alert("You Win! Scissors beat Paper!");
            return 1;
        }
    }
    else {
        alert("Invalid input!")
    }
}

(function game() {
    let wins = 0;
    for (let i = 0; i < 5; i++) {
        wins += playRound();
    }
    if (ties === 5) {
        alert("You tied!")
        return;
    }
    let losses = 5 - wins - ties;
    if ( wins > losses) {
        alert("You win!");
        return;
    }
    else {
        alert("You lose!")
    }
})();