Javascript: while loop neverending

Question

I've been trying to fix this loop, but apparently it doesn't recognize when the input is right. Am I using the right kind of loop here?

var userChoice = prompt("Do you choose rock, paper or scissors?") 
if (userChoice !== "rock", "paper", "scissors") {
 do {
 prompt("Invalid answer. Please choose rock, paper or scissors.");
 } while (userChoice !== "rock", "paper", "scissors");
} else { 

• Pointy: You don't assign the result of the second prompt() call back to userChoice, so userChoice never changes.
• Teemu: ... + you're comparing against "scissors" only.
• James Thorpe: userChoice !== "rock", "paper", "scissors" isn't doing what you think it is
• James Thorpe: I'm also going to preemptively guess that your next question will be why the code in the else block only runs when they make a correct choice first time - you probably don't need the else at all, with the code in that block immediately following the if block instead. (unless it contains code to congratulate them on making a correct choice first time...?)
• John Dvorak: @JamesThorpe in short, the question is pretty much too broad, as good answers would have to fix all of the issues, and it's also caused by a "typo" and a partial duplicate of the question you linked.

Answer 1

There are 2 major issues here:

• You need to re-assign userChoice inside your do-while loop:

  userChoice = prompt("Invalid answer. Please choose rock, paper or scissors.");
  

• Your comparison is off and won't work, use this instead in your if and while:

  (userChoice != "rock" && userChoice != "paper" && userChoice != "scissors")
  

• h2ooooooo: An alternative is using Array.indexOf: ['rock', 'paper', 'scissors'].indexOf('no') (which results in -1)
• Idos: True and thanks for that, although probably too advanced for the OP who I assume is a beginner in JS
• jmcgriz: Also probably too advanced, but regex works well here as well var userChoice = prompt("Do you choose rock, paper or scissors?") ; var testrgx = /^(rock|paper|scissors)$/; if (testrgx.test(userChoice)){ } else { //while loop in here }
• John Dvorak: @jmcgriz not only too advanced, but also less readable and probably slower than the array approach.
• tklein: Thanks! And sorry for the newbie question, but I was really sweating it out.