Question 50858 in Javascript Question posted in
A very good W3school tutorial can be found here.

Checking equality of two strings is not working properly in javascript

function playerSelection() {
     let choice = prompt("Enter you choice.");
     while(choice != "rock" && choice != "paper" && choice != "scissor"){
        alert("Wrong entry");
        playerSelection();
     }
return choice;
   }

This code works just fine until you enter a string that makes the while loop condition true. Once it enters the while loop after an incorrect entry and prompts you to enter another string even if you enter a correct string, it keeps displaying the "wrong entry" alert and shows the prompt until you reload the page. What is going on?

I tried manipulating the logical operator but that does not seem to help. My guess is it has something to do with the recursion, but I have no clue what it is.

Tags:

3

Answers


  1. 0

    it’s because each new call to playerSelection() creates a new call context that stores its own local variables and parameters. try this out:

    playerSelection() {
    let choice = prompt('Enter your choice:')

    while (choice != 'rock' && choice != 'paper' && choice != 'scissors') {
        alert('Wrong entry')
        choice = prompt('Enter your choice:')
    }

    return choice
}

    or if you want with recursion

    playerSelection() {
    let choice = prompt('Enter your choice:')

    if (choice == 'rock' || choice == 'paper' || choice == 'scissors') {
        return choice
    } else {
        alert('wrong entry')
        return playerSelection()
    }
}
    Login or Signup to reply.
  2. 0

    You don’t need to call the function again. The "prompt"-method already does what you (as I am guessing) want to do.
    Do this instead:

    function playerSelection(){
    let choice;
    do{
        choice = prompt("Enter your choice: ");
        if(choice != "rock" && choice != "paper" && choice != "scissor"){
            alert("Wrong entry!");
        }
    }while(choice != "rock" && choice != "paper" && choice != "scissor");
    return choice;
}
    Login or Signup to reply.
  3. 0

    Your variable should be declared before the function as here :

                let choice;
            function playerSelection(){
            choice = prompt("Enter your choice.");
            while(choice != "rock" && choice != "paper" && choice != "scissor"){
                alert("Wrong entry");
                playerSelection();
            }
            return choice;
            }

            let result = playerSelection();
            alert("result = " + result);
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search