JavaScript - How to Wait / SetTimeOut / Sleep / Delay

Question

This again is my Rock Paper Scissors game.

At present state the user can't see what's happening because after being prompted for input(Rock, Paper or Scissors) they are immediately reprompted.

The question is how can I make the program delay such that they at least can read what's going on.

I've read that sleep() does not exist in JavaScript. I'm trying to use setTimeOut however, the setTimeOut is causing the program to not run.

Any ideas on how I can delay the next user input after the first user input. This can be done via any JS solution.

This is my present code

function playUntil(rounds) {
        var playerWins = 0;
        var computerWins = 0;
        setTimeout(function() {
        while ((playerWins < rounds) && (computerWins < rounds)) {
          var computerMove = getComputerMove();
          var winner = getWinner(playerMove, computerMove);
          console.log('The player has chosen ' + playerMove + '. The computer has chosen ' + computerMove);
          if (winner === "Player") {
              playerWins += 1; 
          } 
          else if (winner === "Computer") {
              computerWins += 1;
          } 
          if ((playerWins == rounds) || (computerWins == rounds)) {
              console.log("The game is over! The " + winner + " has taken out the game!");
              console.log("The final score was Player - [" + playerWins + "] to Computer - [" + computerWins + "]");
          }
          else {
              console.log(winner + ' takes the round. It is now ' + playerWins + ' to ' + computerWins);
          }
          }
      return [playerWins, computerWins]
    ;},5000);
    }

*"I'm trying to use setTimeOut however, it's throwing an error"*... and that error is? — Phil, Feb 22 '16 at 00:45
If your inputs to a tic tac toe game are rock, paper and scissors, then you have much bigger problems than this. — JK., Feb 22 '16 at 00:47
Guys don't vote down a question so quickly. Now it's simply not going to get answered and it's a very valid question — Ash, Feb 22 '16 at 00:55
*setTimeout* only runs once. You can call it conditionally after each round, or use *setInterval* and cancel it after the last round. — RobG, Feb 22 '16 at 00:55
Thankyou for the first non-troll answer @RobG. Looking into this now — Ash, Feb 22 '16 at 00:58

score 23 · Answer 1 · answered Feb 22 '16 at 01:00

23

You cannot return a value for a parent function on a setTimeout, setInterval or another child function because have different scopes.

You can use promises instead: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise

Bad:

function x () {
  setTimeout(function () {
     return "anything";
  }, 5000);
}

Using promises:

function x () {
  return new Promise(function (resolve, reject) {
    setTimeout(function () {
      resolve("anything");
    }, 5000);
  });
}

Then you can call function like:

x()
.then(
  function (result) {
    alert(result); // Do anything.
  }
);

PD: I have bad English, I'm sorry!.

answered Feb 22 '16 at 01:00

jgdev

509
3
7

Thanks jgdev, I'm just checking this solution now! :) – Ash Feb 22 '16 at 01:07
While promises are a good idea, they are a new feature in ECMAScript 2015 so not supported in a good many browsers in use (including IE). *setTimeout* and *setInterval* work everywhere. – RobG Feb 22 '16 at 01:31
Yes sorry I looked into this and people don't recommend it. Sorry jgdev. I really appreciate the idea though! I'm still trying to work out how setTimeout or setInterval would work – Ash Feb 22 '16 at 03:47
You can use polyfill for those browsers (although by now all major browsers have support) – WorldSEnder Feb 12 '18 at 08:04

score -13 · Accepted Answer · answered Feb 22 '16 at 06:37

-13

This took me a long time to figure out but here was the solution.

Create this function

function sleep(miliseconds) {
    var currentTime = new Date().getTime();
    while (currentTime + miliseconds >= new Date().getTime()) {
    }
}

Add this into my code where I wanted the delay

sleep(3000)

answered Feb 22 '16 at 06:37

Ash

217
1
2
8

23

Please don't do this - it freezes the entire page while sleeping. – fuzzything44 Feb 11 '18 at 20:28

JavaScript - How to Wait / SetTimeOut / Sleep / Delay

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