Question 267659 in Javascript Question posted in
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How can I get a prompt information and use it inside a function in JavaScript?

I’m trying to create a rock, paper and scissors game using JavaScript, in the game I need to get a user choice (rock, paper or scissors) and a random computer choice (rock, paper or scissors), compare these choices and show a winner. But I can’t get the user choice to compare with the computer choice.

I create a function getUserChoice() with a prompt to get a user choice and use the choice inside the function playRound () but the program don’t show the prompt on the scream.

How can I fix this? and if I fix this the app will work?

<script>
            
            function getUserChoice() {
                let userChoice = window.prompt('rock, paper or scissors?')
            }
           
                       
            function getComputerChoice() {
                let computerChoice = Math.random; 
                    if (computerChoice < 0.34){return 'rock';} 
                    else if (computerChoice <= 0.67){return 'paper';}
                    else {return 'scissors';}
                
            }
                            
            
            function playRound(userChoice , computerChoice) {

                const playerSelection = getUserChoice();
                const computerSelection = getComputerChoice();
                
                    if (playerSelection === 'rock' && computerSelection === 'scissors') {
                    console.log('You win! Rock beats Scissors')
                    }
                    else if (playerSelection === 'scissors' && computerSelection === 'paper') {
                        console.log('You win! Scissors beats Paper')
                    }
                    else if(playerSelection === 'paper' && computerSelection === 'rock') {
                        console.log('You win! Paper beats Rock')
                    }
                    
                    else if(playerSelection === 'scissors' && computerSelection === 'rock') {
                        console.log('You lose! Rock beats Scissors')
                    }
                    
                    else if(playerSelection === 'paper' && computerSelection === 'scissors') {
                        console.log('You lose! Scissors beats Paper')
                    }
                    
                    else if (playerSelection === 'rock' && computerSelection === 'paper') {
                        console.log('You lose! Paper beats Rock')
                    }
                    
                    else {
                        console.log('Tie')
                    }
                }               
    </script>
Tags:

2

Answers


  1. 0

    Functions return undefined by default. To return another value, use explicit return statement.

    function getUserChoice() {
    let userChoice = window.prompt('rock, paper or scissors?')
    return userChoice
}

    Then don’t forget to excute playRound(getUserChoice(), getComputerChoice()) when a round starts.

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  2. 0

    Ok there are 3 issues here.

    first of all getUserChoice doesn’t return anything.

    secondly you haven’t called Math.random in getComputerChoice but made a reference to that Math.random method.

    and lastly you haven’t called the playRound() function.

    so if we fix these issues, your code should work just fine.

                function getUserChoice() {
                return window.prompt('rock, paper or scissors?')
            }
           
                       
            function getComputerChoice() {
                let computerChoice = Math.random(); 
                    if (computerChoice < 0.34){return 'rock';} 
                    else if (computerChoice <= 0.67){return 'paper';}
                    else {return 'scissors';}
                
            }
                            
            
            function playRound(userChoice , computerChoice) {

                const playerSelection = getUserChoice();
                const computerSelection = getComputerChoice();
                
                    if (playerSelection === 'rock' && computerSelection === 'scissors') {
                    console.log('You win! Rock beats Scissors')
                    }
                    else if (playerSelection === 'scissors' && computerSelection === 'paper') {
                        console.log('You win! Scissors beats Paper')
                    }
                    else if(playerSelection === 'paper' && computerSelection === 'rock') {
                        console.log('You win! Paper beats Rock')
                    }
                    
                    else if(playerSelection === 'scissors' && computerSelection === 'rock') {
                        console.log('You lose! Rock beats Scissors')
                    }
                    
                    else if(playerSelection === 'paper' && computerSelection === 'scissors') {
                        console.log('You lose! Scissors beats Paper')
                    }
                    
                    else if (playerSelection === 'rock' && computerSelection === 'paper') {
                        console.log('You lose! Paper beats Rock')
                    }
                    
                    else {
                        console.log('Tie')
                    }
                }          
                
                playRound();
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