More efficient choice comparison for Rock Paper Scissors

Question

This is an ongoing school project that I would like to improve. The point is to make the code as efficient (or short) as possible. I would like to reduce it by finding an alternative to all the else ifs when comparing the computer's choice with the user's choice.

Here is the code:

let weapons = ["Rock", "Paper", "Scissors"];
let random = Math.floor(Math.random()*3);
let chosenOne = weapons[random];

let rps = prompt("Welcome to Rock, Paper, Scissors. Would you like to play?" 
+ '\n' + "If you do, enter number 1." + '\n' + "If you don't, enter number 
2.");

if (rps === "1") {
    alert("Remember:" + '\n' + " - Rock beats the scissors" + '\n' + " - 
    Paper beats the rock" + '\n' + " - The scissors cut the paper");

let weapon = prompt("Make your choice:" + '\n' + "Rock, Paper, Scissors");
    weapon = weapon.charAt(0).toUpperCase() + weapon.slice(1).toLowerCase();
    alert("You chose: " + weapon + '\n' + "The computer chose: " + 
    chosenOne);
if (weapon === chosenOne) {
        alert("It's a tie! Try again to win!");
    } else if (weapon === "Rock" && chosenOne === "Paper") {
        alert("You lost! Paper beats the rock.");
    } else if (weapon === "Paper" && chosenOne === "Scissors") {
        alert("You lost! The scissors cut the paper.");
    } else if (weapon === "Scissors" && chosenOne === "Rock") {
        alert("You lost! The rock beats the scissors.");
    } else if (weapon === "Scissors" && chosenOne === "Paper") {
        alert("You won! Scissors cut the paper.");
    } else if (weapon === "Paper" && chosenOne === "Rock") {
        alert("You won! Paper beats the rock.");
    } else if (weapon === "Rock" && chosenOne === "Scissors") {
        alert("You won! The rock beats the scissors.");
    }
} else if (rps === "2") {
    alert("Thanks for visiting! See you later.");
} else if (rps !== "1" || rps !== "2") {
    alert("Invalid option. Closing game.");
}

I have thought about using switch statements, but since we are still beginners, I haven't grasped the subject fully. Any help is appreciated.

Answer 1

You can define an object that define if your move is weak or strong against another. Example:

const myChoice = 'Rock'
const enemyChoice = 'Scissors' 

const weapons = {
   Rock: {weakTo: 'Paper', strongTo: 'Scissors'},
   Paper: {weakTo: 'Scissors', strongTo: 'Rock'},
   Scissors: {weakTo: 'Rock', strongTo: 'Paper'}
}

if (weapons[myChoice].strongTo === enemyChoice) {
    // I won
    return;
}

if (weapons[myChoice].weakTo === enemyChoice) {
    // I Lost
    return;
}

// tie