Executing setTimeout() in loop takes effect only in the first iteration [duplicate] - javascript

I'm trying to make a few things scroll down the screen in javascript, however, upon execution, it just says a little and displays everything at once. So it's not clearing with the $("#Menu").html('') function and the setTimeout(function {},500) is just setting a timeout for the entire page instead of the code segment.
var MenuData = [
{'Name':'pictures','x':'30'},
{'Name':'blog','x':'50'},
{'Name':'contact','x':'42'}
]
;
var PositionArray = new Array();
$(document).ready(function () {
for (var count = 0; count < 1000; count++) {
$("#Menu").html('');
if (PositionArray[count] != null) {
PositionArray[count]++;
} else {
PositionArray[count] = 0;
}
setTimeout(function () {
for (var i in MenuData) {
$("#Menu").append('<div style="position:relative; left:' + MenuData[i].x + 'px; top:' + PositionArray[i] + 'px; ">123</div>');
}
}, 500);
}
});
Here's the fiddle: http://jsfiddle.net/LbjUP/
Edit: There was a little bit of error in the code that doesn't apply to the question. Here's the new one: http://jsfiddle.net/LbjUP/1/, I just moved PositionArray[count] to the setTimeout function as PositionArray[i]

As stated in the comments, you are creating 1000 timeouts for 500 ms at the same time - after 500 ms all of them will be executed. What you want is to increase the timeout for every scheduled function:
setTimeout(function() {
// do something
}, count * 500);
However, creating 1000 timeouts at once is not a that good idea. It would be better to use setInterval or call setTimeout "recursively" until a count of 1000 is reached, so that you only have one active timeout at a time.
var count = 0;
function update() {
// do something
if (++count < 1000)
setTimeout(update, 500);
// else everything is done
}
update();
Also, if you intend to create timeouts in a loop, be sure to be familiar with closures and their behavior when accessing counter variables after the loop ran.

Try
function recurse ( cnt ) {
for (var i in MenuData) {
$("#Menu").append('<div style="position:relative; left:' + MenuData[i].x + 'px; top:' + PositionArray[i] + 'px; ">123</div>');
}
if (cnt < 1000){
setTimeout(function () { recurse(cnt + 1); }, 500);
}
}
$("#Menu").html('');
if (PositionArray[count] != null) {
PositionArray[count]++;
} else {
PositionArray[count] = 0;
}
recurse(0);

You can also use setInterval
let i = 0;
const interval = setInterval(() => {
console.log(i);
i++;
if (i >= 10) {
clearInterval(interval);
}
}, 1000);`

Related

How to get clearInterval() to work in a loop in JavaScript

So I'm trying to get a function to run once every second, and then after four seconds I want it to stop using clearInterval()
function dotdotdot(){
var x = 0;
setInterval(function(){
if (x>=3){
torpWri = torpWri + ".";
document.getElementById("torpTxt").innerHTML = torpWri;
x++;
}
else{
x = 0;
clearInterval();
}
},1000);
}
This is my function and it should stop after four seconds and then reset x to 0 for when I call it again.
function loadButton(){
torpWri = "Torpedo Loading"
if(torpLoadAmount[arNum]<5){
torpLoadAmount[arNum]++;
torpAmount--;
document.getElementById("torpCnt").innerHTML = torpAmount;
document.getElementById("torpTxt").style.visibility = "visible";
document.getElementById("butunload").disabled=true;
document.getElementById("butfire").disabled=true;
document.getElementById("torpTxt").innerHTML = torpWri;
dotdotdot();
}
else{
document.getElementById("torpTxt").style.visibility = "visible";
document.getElementById("torpTxt").innerHTML = "Torpedo Bay Full";
}
timer3();
}
This is how I'm calling it.
I'm just needed to know why it isn't running the function dotdotdot(); every second and then stopping after four. Then when I call it again it should all just reset. But it's not running...
I've been searching for a while and haven't found anything, so I came here.
(Also, please don't comment on my other code, I know there are probably easier ways to do it, but this is what I'm working with right now.)
setInterval returns a timerID, which needs to be passed to clearInterval.
var ticks = 0;
var intervalID = setInterval(function() {
if (++ticks == 4) {
clearInterval(intervalID);
}
}, 1000);
You could also use setTimeout instead, and just not schedule a new tick when the condition is met.
setTimeout(function callback(ticks) {
if (ticks > limit) {
return;
}
setTimeout(callback, 0, ++ticks);
}, 1000, 0)
You need to store the handle / intervalId for the interval when it is set and then use it when you want to clear the interval:
function dotdotdot(){
var x = 0;
var intervalId = -1;
intervalId = setInterval(function(){
if (x>=3){
torpWri = torpWri + ".";
document.getElementById("torpTxt").innerHTML = torpWri;
x++;
} else {
x = 0;
clearInterval(intervalId);
}
},1000);
}
More info: https://developer.mozilla.org/en-US/Add-ons/Code_snippets/Timers
setInterval will return a timerid. So do like
var timer = setInterval(fun......)
Then
clearInterval(timer)

How to Stop Interval After on Full Run

Can you please take a look at this demo and let me know how I can stop the animation and interval after reaching 100% and filling the progress bar
I tried adding clearInterval(myVar); to the end of interval but this stops incrementting the percentage text
$(".progress-bar").animate({
width: "100%"
}, 3000);
var myVar=setInterval(function(){myTimer()},1);
var count = 0;
function myTimer() {
if(count < 100){
$('.progress').css('width', count + "%");
count += 0.05;
document.getElementById("demo").innerHTML = Math.round(count) +"%";
// code to do when loading
}
else if(count > 99){
// code to do after loading
count = 0;
}
}
clearInterval(myVar);
Don't use a timer for this. jQuery provides a way for you to listen to the progress of the animation:
$(".progress-bar").animate({
width: "100%"
},{
duration: 3000,
progress: function(_, progr) {
$('#demo').text( Math.round(100 * progr));
}
});
See your updated fiddle
NB: I changed your demo element to a span, as a p will break the % to the next line.
You need to put the code of clearing the interval in the block where you handle the finishing of loading.
var myVar = setInterval(function() {
myTimer()
}, 1);
var count = 0;
function myTimer() {
if (count < 100) {
$('.progress').css('width', count + "%");
count += 0.05;
document.getElementById("demo").innerHTML = Math.round(count) + "%";
// code to do when loading
} else if (count > 99) {
// code to do after loading
count = 0;
// loading is done, clear the interval
clearInterval(myVar);
}
}

skip timer in JavaScript interval

I currently have a function that executes some code within a setInterval method. This is working as expected. The problem is I conditionally execute code within this timer. If the condition is not met it will still wait the timeout until trying again. Is there a way of 'skipping' the delay and only executing it when the condition is met.
You will notice in my demo there is a prolonged delay between outputting paragraph results 4 and 8 (as its delaying in between the checks). I would like there to be a consistent delay throughout the whole procedure.
DEMO https://jsfiddle.net/jdec4h0x/
var intAdd = setInterval(function() {
refIndex++
if(refIndex >= predefinedMaxLimit) {
refIndex = 0;
loopedThrough = true;
}
// if this exists then increment refIndex and try again
if (loopedThrough || !$(".myclass[data-mydata1='" + predefinedData2 + "'][data-mydata2='" + refIndex + "']").length) {
counter++;
$('p').last().after('<p>IN Cond Ref = ' + refIndex + '</p>');
// ** js code within this tiemout **
if (counter >= predefinedOutputP) clearInterval(intAdd);
}
}, 500);
You can't change the delay of the interval. Either you destroy and create an interval as Kevin B said or you use setTimeout, which you have to call every time anyway, and then use a delay or another depending on a condition.
/* ... */
if (conditionIsMet) intAdd = setTimeout(function() {}, 1000);
else intAdd = setTimeout(function() {}, 1);
/* ... */
An example here
There are multjple approaches as pointed out by other users.
I would use setTimeout. I'd put this in a function that resides within a loop. You can do this with a while loop. This then gives the the ability to break out when the condition is met. you will need to increment the timer on each loop.
Fiddle https://jsfiddle.net/jdec4h0x/4/
while (progress) {
refIndex++
if (refIndex >= predefinedMaxLimit) {
refIndex = 0;
loopedThrough = true;
}
if (loopedThrough || !$(".myclass[data-mydata1='" + predefinedData2 + "'][data-mydata2='" + refIndex + "']").length) {
counter++;
myTimer = myTimer + 500;
console.log(refIndex);
myFunction(refIndex);
if (counter >= predefinedOutputP) {
$('p').last().after('<p>Cleared Interval</p>');
progress = false;
}
}
}
function myFunction(ref) {
setTimeout(function() {
$('p').last().after('<p>IN Cond Ref = ' + ref + '</p>');
// ** js code within this tiemout **
}, myTimer)
}

Reduce setTimeout time relative to time left

I'm making a random "spinner" that loops through 8 divs and add a class active like this:
https://jsfiddle.net/9q1tf51g/
//create random setTimeout time from 3sec to 5sec
var time = Math.floor(Math.random() * (5000 - 3000 + 1)) + 3000;
var exit = false;
function repeat(){
//my code
if(!exit){
setTimeout(repeat, 50);
}
}
My problem is, I want the function repeat to end slowly, to create more suspense. I think I can do this by raising the 50 from the timeout but how can I do this accordingly to the time left?
Thanks in advance!
You can try this.
$('button').on('click', function(){
var time = Math.floor(Math.random() * (5000 - 3000 + 1)) + 3000;
var anCounter = 1;
var anState = "positive";
var exit = false;
//var time1 = 50000;
setInterval(function(){time = time-1000;}, 1000);
function repeat(){
if(anCounter>7 && anState=="positive"){ anState="negative"}
if(anCounter<2 && anState=="negative"){ anState="positive"}
$('div[data-id="'+anCounter+'"]').addClass('active');
$('div').not('div[data-id="'+anCounter+'"]').removeClass('active');
if(anState=="positive"){anCounter++;}else{anCounter--;}
if(!exit){
if(time <1000)
setTimeout(repeat, 300);
else if(time< 2000)
setTimeout(repeat, 100);
else setTimeout(repeat, 50);
}
}
repeat();
setTimeout(function(){
exit=true;
},time);
});
Once you know that you need to exit the flow (exit is true ) you can trigger some animation by creating a dorm linear serials of you code. Usually this animation should not last more than 2 sec.
You were kind of on the right track but it'd be easier to check the time you've passed by and increment accordingly at a fixed rate. I set it to increase by 50ms every iteration but you could change that to whatever you like.
Fiddle Demo
Javascript
$('button').on('click', function() {
var time = Math.floor(Math.random() * (5000 - 3000 + 1)) + 3000;
var anCounter = 1;
var anState = "positive";
var elapsed = 0;
var timer;
function repeat(timeAdded) {
if (anCounter > 7 && anState == "positive") {
anState = "negative"
}
if (anCounter < 2 && anState == "negative") {
anState = "positive"
}
$('div[data-id="' + anCounter + '"]').addClass('active');
$('div').not('div[data-id="' + anCounter + '"]').removeClass('active');
if (anState == "positive") {
anCounter++;
} else {
anCounter--;
}
if (elapsed < time) {
timer = setTimeout(function() {
repeat(timeAdded + 50);
}, timeAdded);
elapsed += timeAdded;
}
else {
clearTimeout(timer);
}
}
repeat(0);
});
You can add a parameter called intTime to your function repeat and inside that function you can adjust the next timeout and call the repeat function with the new timeout. each time it gets called it will take 20 ms longer. however you adjust the increment by changing the 20 in
var slowDown=20; to a different number.
var slowDown=20;
setTimeout ("repeat",50);
function repeat(intTime){
//my code
if(!exit){
intTime=Math.floor (intTime)+slowDown;
setTimeout(repeat(intTime), intTime);
}
}
And then you will need to create another timeout for the exit.
var time = Math.floor(Math.random() * (5000 - 3000 + 1)) + 3000;
var exit = false;
setTimeout ("stopSpinning",time);
function stopSpinning(){
exit = true;
}
so the whole thing should look something like this
var slowDown=20;
var time = Math.floor(Math.random() * (5000 - 3000 + 1)) + 3000;
var exit = false;
setTimeout ("stopSpinning",time);
setTimeout ("repeat",50);
function repeat(intTime){
//my code
if(!exit){
intTime=Math.floor (intTime)+20;
setTimeout(repeat(intTime), intTime);
}
}
function stopSpinning(){
exit = true;
}
Fiddle Demo
Linear deceleration: //values are just an example:
add a var slowDown = 0; inside the click event handler
add slowDown += 1; inside the repeat function
pass 50+slowDown to setTimeout
Curved deceleration:
add a var slowDown = 1;and a var curveIndex = 1.05 + Math.random() * (0.2); // [1.05-1.25)inside the click event handler
add slowDown *= curveIndex; inside the repeat function
pass 50+slowDown to setTimeout

Javascript array is not recognizing called variable

function slideShow() {
var pageSplash = document.getElementById('splash');
var image = ["pic1.jpg", "pic2.jpg", "pic3.jpg", "pic4.jpg"];
var i = 0;
while (i <= image.length) {
if (i > image.length) {
i = 0;
}
i += 1;
pageSplash.innerHTML = '<img id ="splashImage" src="file:///C:/JonTFS/JonGrochCoding/Javascript%20Practical%20Test/' + image[i] + '">';
setTimeout('slideShow', 5000);
}
}
I'm unsure why my i variable is not being recognized as the i variable from the rest of the function, so when ever I try to run my while loop it get's an error message saying that it's undefined.
I think you want setInterval instead of setTimeout, and you want you be careful that you increment i after you you update innerHTML.
function slideShow() {
var pageSplash = document.getElementById('splash');
var image = ["pic1.jpg", "pic2.jpg", "pic3.jpg", "pic4.jpg"];
var i = 0;
setInterval(function () {
if (i === image.length) {
i = 0;
}
pageSplash.innerHTML = '<img id ="splashImage" src="file:///C:/JonTFS/JonGrochCoding/Javascript%20Practical%20Test/' + image[i] + '">';
i++;
}, 5000)
}
slideShow();
You don't need a while loop. You don't need to reset i. You don't need to set innerHTML.
Click Run code snippet... to see how this works. More explanation below the code
function slideShow(elem, images, delay, i) {
elem.src = images[i % images.length];
setTimeout(function() {
slideShow(elem, images, delay, i+1);
}, delay);
}
// setup slideshow 1
slideShow(
document.querySelector('#slideshow1 img'), // target element
[ // array of images
'http://lorempixel.com/100/100/animals/1/',
'http://lorempixel.com/100/100/animals/2/',
'http://lorempixel.com/100/100/animals/3/',
'http://lorempixel.com/100/100/animals/4/',
'http://lorempixel.com/100/100/animals/5/',
'http://lorempixel.com/100/100/animals/6/'
],
1000, // 1000 ms delay (1 second)
1 // start on slide index 1
);
// setup slideshow 2
slideShow(
document.querySelector('#slideshow2 img'), // target element
[ // array of images
'http://lorempixel.com/100/100/nature/1/',
'http://lorempixel.com/100/100/nature/2/',
'http://lorempixel.com/100/100/nature/3/',
'http://lorempixel.com/100/100/nature/4/',
'http://lorempixel.com/100/100/nature/5/',
'http://lorempixel.com/100/100/nature/6/'
],
500, // 500 ms delay
1 // start on slide 1
);
#slideshow1, #slideshow2 {
width: 150px;
display: inline-block;
}
<div id="slideshow1">
<h2>Animals</h2>
<p>(1000 ms delay)</p>
<!-- initial image -->
<img src="http://lorempixel.com/100/100/animals/1/">
</div>
<div id="slideshow2">
<h2>Nature</h2>
<p>(500 ms delay)</p>
<!-- initial image -->
<img src="http://lorempixel.com/100/100/sports/1/">
</div>
This is a huge improvement because your slideshow function is reusable. It means you can use the same function for any slideshow you want. You can even run multiple slideshows on the same page, as I have demonstrated here.
As others have pointed out, the while loop is unnecessary and, as I pointed out, the setTimout was incorrectly written. The following simplifies your code significantly:
var i = 0;
function slideShow() {
var pageSplash = document.getElementById('splash');
var imageArray = ["pic1.jpg", "pic2.jpg", "pic3.jpg", "pic4.jpg"];
if(i < imageArray.length) {
pageSplash.innerHTML = '<img title='+ imageArray[i] + ' id ="splashImage" src="file:///C:/JonTFS/JonGrochCoding/Javascript%20Practical%20Test/' + imageArray[i] + '">';
}
i++;
}
setInterval(slideShow, 2000);
See: https://jsfiddle.net/dauvc4j6/8/ for a working version.
setTimeout calls the function again so you're re-initializing i to 0 every time you call it. Since you can use setTimeout to call the function recursively you don't need the while loop. Pull i out of the function altogether and make it a global variable.
//i should be global
var i = 0;
function slideShow() {
var pageSplash = document.getElementById('splash');
var image = ["pic1.jpg", "pic2.jpg", "pic3.jpg", "pic4.jpg"];
if (i >= image.length) {
i = 0;
}
i += 1;
pageSplash.innerHTML = '<img id ="splashImage" src="file:///C:/JonTFS/JonGrochCoding/Javascript%20Practical%20Test/' + image[i] + '">';
//set timeout is going to call slideShow again so if it's in the function it will call recursively, if you wanted to stop after a certain point you could nest setTimeout in an if
setTimeout(slideShow, 5000);
}
//you need to initially call the function
slideShow();

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