I'm having problems getting my simple Rock Paper Scissors game to display the winner of each game. Please help.

const choices = ["rock", "paper", "scissors"];

// GETTING USER INPUT
const userInput = prompt("Do you choose rock, paper or scissors?"); 
    if(userInput ==="paper" || userInput ==="rock" || userInput ==="scissors"){
        console.log("You chose "   `${userInput}`);
    } else {
        console.log("Error! Try again!");
    }

// GETTING COMPUTER INPUT
const computerInput = choices[Math.floor(Math.random() * 3)]; 
console.log("Computer chose"   ` ${computerInput}`);

    if (computerInput <= 0.33) {
        computerInput = "rock";
    }
    else if (computerInput > 0.66) {
        computerInput = "paper";
    }
    else {
        computerInput = "scissors";
    }

// DECLARE WINNER 
const winner = declareWinner (userInput, computerInput);

    if (userInput === 'rock' && computerInput === 'paper') {
        console.log ('You lose! Rock beats Paper');    
    }
    else if (userInput === 'scissors' && computerInput === 'paper') {
        console.log ('You win! Scissors beats Paper');
    }
    else  {
        console.log ('You tie!');
    } 

I get an error message "Uncaught TypeError: Assignment to constant variable. at index.js:22:23" in the line of code below ```computerInput = "scissors"; `

else {
        computerInput = "scissors";
    };

What am I doing wrong?

CodePudding user response：

There were two problems with the code:-

• You are doing choices[Math.floor(Math.random() * 3)]; which results in a random value from choices array, so there is no need for multiple if-else statements that were after it.
• You were missing the declareWinner function declaration.

Also, You are missing some conditions in declareWinner function, like userInput === 'paper' && computerInput === 'rock', userInput === 'rock' && computerInput === 'scissors' etc.

const choices = ["rock", "paper", "scissors"];

// GETTING USER INPUT
const userInput = prompt("Do you choose rock, paper or scissors?");
if (userInput === "paper" || userInput === "rock" || userInput === "scissors") {
  console.log("You chose "   `${userInput}`);
} else {
  console.log("Error! Try again!");
}

// GETTING COMPUTER INPUT
let computerInput = choices[Math.floor(Math.random()*3)];
console.log("Computer chose"   ` ${computerInput}`);

// DECLARE WINNER 
const winner = declareWinner(userInput, computerInput);

function declareWinner(userInput, computerInput) {
  if (userInput === 'rock' && computerInput === 'paper') {
    console.log('You lose! Rock beats Paper');
  } else if (userInput === 'scissors' && computerInput === 'paper') {
    console.log('You win! Scissors beats Paper');
  } else {
    console.log('You tie!');
  }
}

Tip:- You can use an object to choose the winner in declareWinner function.

const choices = ["rock", "paper", "scissors"];

// GETTING USER INPUT
const userInput = prompt("Do you choose rock, paper or scissors?");
if (userInput === "paper" || userInput === "rock" || userInput === "scissors") {
  console.log("You chose "   `${userInput}`);
} else {
  console.log("Error! Try again!");
}

// GETTING COMPUTER INPUT
let computerInput = choices[Math.floor(Math.random() * 3)];
console.log("Computer chose"   ` ${computerInput}`);

// DECLARE WINNER 
const winner = declareWinner(userInput, computerInput);

function declareWinner(userInput, computerInput) {
  let win = {
    rock: "scissors",
    paper: "rock",
    scissors: "paper"
  };

  if (win[userInput] === computerInput) {
    console.log(`You won! ${userInput} beats ${computerInput}`);
  } else if (win[computerInput] === userInput) {
    console.log(`You lost! ${computerInput} beats ${userInput}`);
  } else console.log("Tie")
}

CodePudding user response：

You can't change a const value. Use let instead:

let computerInput = choices[Math.floor(Math.random() * 3)];