This function below doesn’t work like I want it to; being a JS novice I can’t figure out why.
I need it to wait 5 seconds before checking whether the newState is -1.
Currently, it doesn’t wait, it just checks straight away.
function stateChange(newState) {
setTimeout('', 5000);
if(newState == -1) {
alert('VIDEO HAS STOPPED');
}
}
Browser
Here's a solution using the new async/await syntax.
Be sure to check browser support as this is a language feature introduced with ECMAScript 6.
Utility function:
const delay = ms => new Promise(res => setTimeout(res, ms));
Usage:
const yourFunction = async () => {
await delay(5000);
console.log("Waited 5s");
await delay(5000);
console.log("Waited an additional 5s");
};
The advantage of this approach is that it makes your code look and behave like synchronous code.
Node.js
Node.js 16 provides a built-in version of setTimeout that is promise-based so we don't have to create our own utility function:
import { setTimeout } from "timers/promises";
const yourFunction = async () => {
await setTimeout(5000);
console.log("Waited 5s");
await setTimeout(5000);
console.log("Waited an additional 5s");
};
⚠️ Just for the record, you might be tempted to use a wait function to circumvent race conditions (when testing asynchronous code for example). This is rarely a good idea.
You have to put your code in the callback function you supply to setTimeout:
function stateChange(newState) {
setTimeout(function () {
if (newState == -1) {
alert('VIDEO HAS STOPPED');
}
}, 5000);
}
Any other code will execute immediately.
You really shouldn't be doing this, the correct use of timeout is the right tool for the OP's problem and any other occasion where you just want to run something after a period of time. Joseph Silber has demonstrated that well in his answer. However, if in some non-production case you really want to hang the main thread for a period of time, this will do it.
function wait(ms){
var start = new Date().getTime();
var end = start;
while(end < start + ms) {
end = new Date().getTime();
}
}
With execution in the form:
console.log('before');
wait(7000); //7 seconds in milliseconds
console.log('after');
I've arrived here because I was building a simple test case for sequencing a mix of asynchronous operations around long-running blocking operations (i.e. expensive DOM manipulation) and this is my simulated blocking operation. It suits that job fine, so I thought I post it for anyone else who arrives here with a similar use case. Even so, it's creating a Date() object in a while loop, which might very overwhelm the GC if it runs long enough. But I can't emphasize enough, this is only suitable for testing, for building any actual functionality you should refer to Joseph Silber's answer.
If you're in an async function you can simply do it in one line:
console.log(1);
await new Promise(resolve => setTimeout(resolve, 3000)); // 3 sec
console.log(2);
FYI, if target is NodeJS you can use this built-in function if you want (it's a predefined promisified setTimeout function):
import { setTimeout } from 'timers/promises';
await setTimeout(3000); // 3 sec
Use a delay function like this:
var delay = ( function() {
var timer = 0;
return function(callback, ms) {
clearTimeout (timer);
timer = setTimeout(callback, ms);
};
})();
Usage:
delay(function(){
// do stuff
}, 5000 ); // end delay
Credits: How to delay the .keyup() handler until the user stops typing?
You should not just try to pause 5 seconds in javascript. It doesn't work that way. You can schedule a function of code to run 5 seconds from now, but you have to put the code that you want to run later into a function and the rest of your code after that function will continue to run immediately.
For example:
function stateChange(newState) {
setTimeout(function(){
if(newState == -1){alert('VIDEO HAS STOPPED');}
}, 5000);
}
But, if you have code like this:
stateChange(-1);
console.log("Hello");
The console.log() statement will run immediately. It will not wait until after the timeout fires in the stateChange() function. You cannot just pause javascript execution for a predetermined amount of time.
Instead, any code that you want to run delays must be inside the setTimeout() callback function (or called from that function).
If you did try to "pause" by looping, then you'd essentially "hang" the Javascript interpreter for a period of time. Because Javascript runs your code in only a single thread, when you're looping nothing else can run (no other event handlers can get called). So, looping waiting for some variable to change will never work because no other code can run to change that variable.
setTimeout(function() {
$('.message').hide();
}, 5000);
This will hide the '.message' div after 5 seconds.
This solution comes from React Native's documentation for a refresh control:
function wait(timeout) {
return new Promise(resolve => {
setTimeout(resolve, timeout);
});
}
To apply this to the OP's question, you could use this function in coordination with await:
await wait(5000);
if (newState == -1) {
alert('Done');
}
Try this:
//the code will execute in 1 3 5 7 9 seconds later
function exec() {
for(var i=0;i<5;i++) {
setTimeout(function() {
console.log(new Date()); //It's you code
},(i+i+1)*1000);
}
}
Best way to create a function like this for wait in milli seconds, this function will wait for milliseconds provided in the argument:
function waitSeconds(iMilliSeconds) {
var counter= 0
, start = new Date().getTime()
, end = 0;
while (counter < iMilliSeconds) {
end = new Date().getTime();
counter = end - start;
}
}
Based on Joseph Silber's answer, I would do it like that, a bit more generic.
You would have your function (let's create one based on the question):
function videoStopped(newState){
if (newState == -1) {
alert('VIDEO HAS STOPPED');
}
}
And you could have a wait function:
function wait(milliseconds, foo, arg){
setTimeout(function () {
foo(arg); // will be executed after the specified time
}, milliseconds);
}
At the end you would have:
wait(5000, videoStopped, newState);
That's a solution, I would rather not use arguments in the wait function (to have only foo(); instead of foo(arg);) but that's for the example.
You can add delay by making small changes to your function ( async and await ).
const addNSecondsDelay = (n) => {
return new Promise(resolve => {
setTimeout(() => {
resolve();
}, n * 1000);
});
}
const asyncFunctionCall = async () {
console.log("stpe-1");
await addNSecondsDelay(5);
console.log("step-2 after 5 seconds delay");
}
asyncFunctionCall();
If you have an asyn function you can do:
await new Promise(resolve => setTimeout(resolve, 5000));
Related
I need to execute 3 functions in a 1 sec delay.
for simplicity those functions are :
console.log('1');
console.log('2');
console.log('3');
I could do this: ( very ugly)
console.log('1')
setTimeout(function () {
setTimeout(function () {
console.log('2')
setTimeout(function () {
console.log('3')
}, 1000)
}, 1000)
}, 1000)
Or I could create an array of functions and use setInterval with global counter.
Is there any elegant way of doing this ?
(p.s. function no.2 is not dependent on function number 1... hence - every sec execute the next function.).
You can use something like this with setTimeout:
var funcs = [func1, func2, func3],
i = 0;
function callFuncs() {
funcs[i++]();
if (i < funcs.length) setTimeout(callFuncs, 1000);
}
setTimeout(callFuncs, 1000); //delay start 1 sec.
or start by just calling callFuncs() directly.
Update
An setInterval approach (be aware of the risk of call stacking):
var funcs = [func1, func2, func3],
i = 0,
timer = setInterval(callFuncs, 1000);
function callFuncs() {
funcs[i++]();
if (i === funcs.length) clearInterval(timer);
}
Assuming you run it on a modern browser or have added support for array.map this is quite concise:
[func1, func2, func3].map(function (fun, index) {
setTimeout(fun, 1000 + index * 1000);
}
setTimeout(function(){console.log('1')}, 1000);
setTimeout(function(){console.log('2')}, 2000);
setTimeout(function(){console.log('3')}, 3000);
There is a new type of function declaration called generators in es6 (a.k.a ecmascript 6, es2015). It is incredibly useful for this situation, and makes your async code look synchronous. es6 is the latest standard of JavaScript as of 2015. It works on modern browsers but you can use Babel and its javascript polyfill to use generators now even on older browsers.
Here is a tutorial on generators.
The function myDelayedMessages below is an example of a generator. Run is a helper function that takes a generator function which it calls and provides a function to advance the generator as the first argument of the generator function that it called.
function delay(time, callback) {
setTimeout(function () {
callback();
}, time);
}
function run(generatorFunction) {
var generatorItr = generatorFunction(resume);
function resume(callbackValue) {
generatorItr.next(callbackValue);
}
generatorItr.next()
}
run(function* myDelayedMessages(resume) {
for(var i = 1; i <= 3; ++i) {
yield delay(1000, resume);
console.log(i);
}
});
This is an overview of the code which is similar to the above tutorial's final overview.
run takes our generator and creates a resume function. run creates a
generator-iterator object (the thing you call next on), providing
resume.
Then it advances the generator-iterator one step to kick
everything off.
Our generator encounters the first yield statement
and calls delay.
Then the generator pauses.
delay completes 1000ms later and calls resume.
resume tells our generator to advance a single step.
Our generator continues from the spot it yielded at then console.logs i, which is 1, then continues the loop
Our generator encounters the second call to yield,
calls delay and pauses again.
delay waits 1000ms and ultimately
calls the resume callback. resume advances the generator again.
Our generator continues from the spot it yielded at then console.logs i, which is 2, then continues the loop.
delay waits 1000ms and ultimately
calls the resume callback. resume advances the generator again.
Our generator continues from the spot it yielded at then console.logs i, which is 3, then continues and the loop finishes.
There are no more calls to yield, the generator finishes executing.
with async/await
const pause = _ => new Promise(resolve => setTimeout(resolve, _));
async function main() {
await pause(1000);
console.log('one');
await pause(1000);
console.log('two');
await pause(1000);
console.log('three');
}
main();
note this works in a loop too
const pause = _ => new Promise(resolve => setTimeout(resolve, _));
async function main() {
for (let i = 0; i < 3; ++i) {
await pause(1000);
console.log(i + 1);
}
}
main();
I think most simple way to do this is to create some closures within a function.
First i'll recall that you have big interest in using setInterval, since the overhead of the setTimeout might have it trigger 10ms off target. So especially if using short (<50ms) interval, prefer setInterval.
So we need to store the function array, the index of latest executed function, and an interval reference to stop the calls.
function chainLaunch(funcArray, time_ms) {
if (!funcArray || !funcArray.length) return;
var fi = 0; // function index
var callFunction = function () {
funcArray[fi++]();
if (fi==funcArray.length)
clearInterval(chainInterval);
} ;
var chainInterval = setInterval( callFunction, time_ms);
}
Rq : You might want to copy the function array ( funcArray = funcArray.slice(0); )
Rq2 : You might want to loop within the array
Rq3 : you might want to accept additionnal arguments to chainlaunch. retrieve them with var funcArgs = arguments.slice(3); and use apply on the functions : funcArray[fi++].apply(this,funcArgs);
Anyway the following test works :
var f1 = function() { console.log('1'); };
var f2 = function() { console.log('2'); };
var f3 = function() { console.log('3'); };
var fArr = [f1, f2, f3];
chainLaunch(fArr, 1000);
as you can see in this fiddle : http://jsfiddle.net/F9UJv/1/
(open the console)
There are here two methods. One with setTimeout and anotherone with setInterval. The first one is better in my opinion.
for(var i = 1; i++; i<=3) {
setTimeout(function() {
console.log(i);
}, 1000*i);
}
// second choice:
var i = 0;
var nt = setInterval(function() {
if(i == 0) return i++;
console.log(i++);
if(i>=3) clearInterval(nt);
}, 1000);
How could I make a loop that pauses for a set amount of time before repeating?
I tried using setTimeout inside of a while loop but that didn't work.
JavaScript is monothreaded, so blocking is to be avoided, that is why so much effort was pourred into the language to standardise Promise and add async / await
This allow to pause code execution without blocking, here how you do it:
// Only available in Node v15+
import { setTimeout as pause } from 'timers/promises'
// if not in node:
const pause = delay => new Promise(s => setTimeout(s, delay))
async function sayHelloEverySeconds() {
while (true) {
await pause(1000) // 1 sec
console.log('hello')
}
}
sayHelloEverySeconds()
But for this exact function, it would be simpler to use setInterval directly:
setInterval(() => console.log('hello'), 1000)
this will execute the function every seconds
You don't need to use async/await functions or promises or a while loop. Call a function and have setTimeout call the function again after a set amount of time.
function loop(count = 0) {
console.log(count);
setTimeout(loop, 1000, ++count);
}
loop();
I have looked around, tried several solutions and have not been able to find a solution :/
What I am looking to do is to have a loop that runs every second which contains events that are fired with different delays depending on the event type and conditions such event type pertains.
Tried self building the infinite loop and logic with while(true) and counters, as well as using setInterval and setTimeout, but all result into the same end result (result: see bottom of the question (based on code examples that use setInterval and setTimeout)).
This result is due to (or at least so I believe, would be nice if someone can confirm) a situation where my callstack contains new every second invocations of the whole loop and X amount of non processed eventY's that have been invoked -> the very first run the behavior is as expected, but after this the callstack begins to accumulate the non processed event Y's and prints them out every second or per the speed of the main loop.
some example code to explain (using setInterval and setTimeout):
function start() {
setInterval(eventList, 1000);
};
function eventList() {
console.log("foo")
eventY();
};
async function eventY() {
await newTimeout(0,5).then(() => {
console.log("bar");
})
};
function newTimeout (minutes, seconds) {
let counter = (minutes*60+seconds)*1000;
return new Promise(resolve => setTimeout(resolve, counter));
}
OR more cumbersome and forceful delay (leads to unpredictable behavior at best and with longer events, the same end result):
function newTimeout(minutes, seconds) {
return new Promise(function(resolve, reject){
let counter = minutes*60+seconds;
let interval = setInterval((() => {
counter--;
if(counter == 0) {
clearInterval(interval);
resolve();
}
}), 1000)
});
};
ALSO tried using just setTimeout to stay away from the setInterval as I understand it is liable to clutter your callstack, ofc the below doesn't change anything now looking at it, but thought I would put it in anyway as I tend to prefer the thought of setTimeout that the function calls itself creating the loop that way.
function start() {
try {
eventList();
} catch (err) {
throw err
} finally {
setTimeout(() => start(), 1000);
}
};
end result is basically:
foo
foo
foo
foo
foo
bar
foo
bar
foo
bar
foo
It's there a way to configure the setInterval method of javascript to execute the method immediately and then executes with the timer
It's simplest to just call the function yourself directly the first time:
foo();
setInterval(foo, delay);
However there are good reasons to avoid setInterval - in particular in some circumstances a whole load of setInterval events can arrive immediately after each other without any delay. Another reason is that if you want to stop the loop you have to explicitly call clearInterval which means you have to remember the handle returned from the original setInterval call.
So an alternative method is to have foo trigger itself for subsequent calls using setTimeout instead:
function foo() {
// do stuff
// ...
// and schedule a repeat
setTimeout(foo, delay);
}
// start the cycle
foo();
This guarantees that there is at least an interval of delay between calls. It also makes it easier to cancel the loop if required - you just don't call setTimeout when your loop termination condition is reached.
Better yet, you can wrap that all up in an immediately invoked function expression which creates the function, which then calls itself again as above, and automatically starts the loop:
(function foo() {
...
setTimeout(foo, delay);
})();
which defines the function and starts the cycle all in one go.
I'm not sure if I'm understanding you correctly, but you could easily do something like this:
setInterval(function hello() {
console.log('world');
return hello;
}(), 5000);
There's obviously any number of ways of doing this, but that's the most concise way I can think of.
I stumbled upon this question due to the same problem but none of the answers helps if you need to behave exactly like setInterval() but with the only difference that the function is called immediately at the beginning.
Here is my solution to this problem:
function setIntervalImmediately(func, interval) {
func();
return setInterval(func, interval);
}
The advantage of this solution:
existing code using setInterval can easily be adapted by substitution
works in strict mode
it works with existing named functions and closures
you can still use the return value and pass it to clearInterval() later
Example:
// create 1 second interval with immediate execution
var myInterval = setIntervalImmediately( _ => {
console.log('hello');
}, 1000);
// clear interval after 4.5 seconds
setTimeout( _ => {
clearInterval(myInterval);
}, 4500);
To be cheeky, if you really need to use setInterval then you could also replace the original setInterval. Hence, no change of code required when adding this before your existing code:
var setIntervalOrig = setInterval;
setInterval = function(func, interval) {
func();
return setIntervalOrig(func, interval);
}
Still, all advantages as listed above apply here but no substitution is necessary.
You could wrap setInterval() in a function that provides that behavior:
function instantGratification( fn, delay ) {
fn();
setInterval( fn, delay );
}
...then use it like this:
instantGratification( function() {
console.log( 'invoked' );
}, 3000);
Here's a wrapper to pretty-fy it if you need it:
(function() {
var originalSetInterval = window.setInterval;
window.setInterval = function(fn, delay, runImmediately) {
if(runImmediately) fn();
return originalSetInterval(fn, delay);
};
})();
Set the third argument of setInterval to true and it'll run for the first time immediately after calling setInterval:
setInterval(function() { console.log("hello world"); }, 5000, true);
Or omit the third argument and it will retain its original behaviour:
setInterval(function() { console.log("hello world"); }, 5000);
Some browsers support additional arguments for setInterval which this wrapper doesn't take into account; I think these are rarely used, but keep that in mind if you do need them.
Here's a simple version for novices without all the messing around. It just declares the function, calls it, then starts the interval. That's it.
//Declare your function here
function My_Function(){
console.log("foo");
}
//Call the function first
My_Function();
//Set the interval
var interval = window.setInterval( My_Function, 500 );
There's a convenient npm package called firstInterval (full disclosure, it's mine).
Many of the examples here don't include parameter handling, and changing default behaviors of setInterval in any large project is evil. From the docs:
This pattern
setInterval(callback, 1000, p1, p2);
callback(p1, p2);
is identical to
firstInterval(callback, 1000, p1, p2);
If you're old school in the browser and don't want the dependency, it's an easy cut-and-paste from the code.
I will suggest calling the functions in the following sequence
var _timer = setInterval(foo, delay, params);
foo(params)
You can also pass the _timer to the foo, if you want to clearInterval(_timer) on a certain condition
var _timer = setInterval(function() { foo(_timer, params) }, delay);
foo(_timer, params);
For someone needs to bring the outer this inside as if it's an arrow function.
(function f() {
this.emit("...");
setTimeout(f.bind(this), 1000);
}).bind(this)();
If the above producing garbage bothers you, you can make a closure instead.
(that => {
(function f() {
that.emit("...");
setTimeout(f, 1000);
})();
})(this);
Or maybe consider using the #autobind decorator depending on your code.
You can set a very small initial delay-time (e.g. 100) and set it to your desired delay-time within the function:
var delay = 100;
function foo() {
console.log("Change initial delay-time to what you want.");
delay = 12000;
setTimeout(foo, delay);
}
To solve this problem , I run the function a first time after the page has loaded.
function foo(){ ... }
window.onload = function() {
foo();
};
window.setInterval(function()
{
foo();
}, 5000);
This example builds on #Alnitak's answer, but uses await Promise for finer granularity of control within the loop cycle.
Compare examples:
let stillGoing = true;
(function foo() {
console.log('The quick brown fox did its thing');
if (stillGoing) setTimeout(foo, 5000);
})();
foo();
In the above example we call foo() and then it calls itself every 5 seconds.
But if, at some point in the future, we set stillGoing to false in order to stop the loop, we'll still get an extra log line even after we've issued the stop order. This is because at any given time, before we set stillGoing to false the current iteration will have already created a timeout to call the next iteration.
If we instead use await Promise as the delay mechanism then we have an opportunity to stop the loop before calling the next iteration:
let stillGoing = true;
(async function foo() {
console.log('The quick brown fox did its thing');
await new Promise(resolve => setTimeout(resolve, 5000));
if (stillGoing) foo();
})();
foo();
In the second example we start by setting a 5000ms delay, after which we check the stillGoing value and decide whether calling another recursion is appropriate.
So if we set stillGoing to false at any point, there won't be that one extra log line printed after we set the value.
The caveat is this requires the function to be async, which may or may not be an option for a given use.
For Those using React, here is how I solve this problem:
const intervalRef = useRef(0);
useEffect(() => {
if (condition is true){
if (intervalRef.current === 0) {
callMyFunction();
}
const interval = setInterval(() => {
callMyFunction();
}, 5_000);
intervalRef.current = interval;
} else {
clearInterval(intervalRef.current);
}
}, [deps]);
// YCombinator
function anonymous(fnc) {
return function() {
fnc.apply(fnc, arguments);
return fnc;
}
}
// Invoking the first time:
setInterval(anonymous(function() {
console.log("bar");
})(), 4000);
// Not invoking the first time:
setInterval(anonymous(function() {
console.log("foo");
}), 4000);
// Or simple:
setInterval(function() {
console.log("baz");
}, 4000);
Ok this is so complex, so, let me put it more simple:
function hello(status ) {
console.log('world', ++status.count);
return status;
}
setInterval(hello, 5 * 1000, hello({ count: 0 }));
If you can use RxJS, there is something called timer():
import { Subscription, timer } from 'rxjs';
const INITIAL_DELAY = 1;
const INTERVAL_DELAY = 10000;
const timerSubscription = timer(INITIAL_DELAY, INTERVAL_DELAY)
.subscribe(() => {
this.updateSomething();
});
// when destroying
timerSubscription.unsubscribe();
With ES2017, it may be preferable to avoid setInterval altogether.
The following solution has a much cleaner execution flow, prevents issues if the function takes longer than the desired time to complete, and allows for asynchronous operations.
const timeout = (delayMs) => new Promise((res, _rej) => setTimeout(res, delayMs));
const DELAY = 1_000;
(async () => {
while (true) {
let start_time = Date.now();
// insert code here...
let end_time = Date.now();
await timeout(DELAY - (end_time - start_time));
}
})();
There's a problem with immediate asynchronous call of your function, because standard setTimeout/setInterval has a minimal timeout about several milliseconds even if you directly set it to 0. It caused by a browser specific work.
An example of code with a REAL zero delay wich works in Chrome, Safari, Opera
function setZeroTimeout(callback) {
var channel = new MessageChannel();
channel.port1.onmessage = callback;
channel.port2.postMessage('');
}
You can find more information here
And after the first manual call you can create an interval with your function.
actually the quickest is to do
interval = setInterval(myFunction(),45000)
this will call myfunction, and then will do it agaian every 45 seconds which is different than doing
interval = setInterval(myfunction, 45000)
which won't call it, but schedule it only
I have the following scenario:
setTimeout("alert('this alert is timedout and should be the first');", 5000);
alert("this should be the second one");
I need the code after the setTimeout to be executed after the code in the setTimeout is executed. Since the code that comes after the setTimeout is not code of my own I can't put it in the function called in the setTimeout...
Is there any way around this?
Is the code contained in a function?
function test() {
setTimeout(...);
// code that you cannot modify?
}
In that case, you could prevent the function from further execution, and then run it again:
function test(flag) {
if(!flag) {
setTimeout(function() {
alert();
test(true);
}, 5000);
return;
}
// code that you cannot modify
}
I came in a situation where I needed a similar functionality last week and it made me think of this post. Basically I think the "Busy Waiting" to which #AndreKR refers, would be a suitable solution in a lot of situations. Below is the code I used to hog up the browser and force a wait condition.
function pause(milliseconds) {
var dt = new Date();
while ((new Date()) - dt <= milliseconds) { /* Do nothing */ }
}
document.write("first statement");
alert("first statement");
pause(3000);
document.write("<br />3 seconds");
alert("paused for 3 seconds");
Keep in mind that this code acutally holds up your browser.
Hope it helps anyone.
Using ES6 & promises & async you can achieve running things synchronously.
So what is the code doing?
1. Calls setTimeOut 1st inside of demo then put it into the webApi Stack
2. Creates a promise from the sleep function using the setTimeout, then resolves after the timeout has been completed;
3. By then, the first setTimeout will reach its timer and execute from webApi stack.
4. Then following, the remaining alert will show up.
function sleep(ms) {
return new Promise(resolve => setTimeout(resolve, ms));
}
async function demo() {
setTimeout("alert('this alert is timedout and should be the first');", 5000);
await sleep(5000);
alert('this should be the second one');
}
demo();
Just put it inside the callback:
setTimeout(function() {
alert('this alert is timedout and should be the first');
alert('this should be the second one');
}, 5000);
No, as there is no delay function in Javascript, there is no way to do this other than busy waiting (which would lock up the browser).
ES6 (busy waiting)
const delay = (ms) => {
const startPoint = new Date().getTime()
while (new Date().getTime() - startPoint <= ms) {/* wait */}
}
usage:
delay(1000)
You can create a promise and await for its fulfillment
const timeOut = (secs) => new Promise((res) => setTimeout(res, secs * 1000));
await timeOut(1000)
Here's a good way to make synchronous delay in your code:
async function yourFunction() {
//your code
await delay(n);
//your code
}
function delay(n) {
n = n || 2000;
return new Promise(done => {
setTimeout(() => {
done();
}, n);
});
}
Found it here Right way of delaying execution synchronously in JavaScript without using Loops or Timeouts!
setTimeout(function() {
yourCode(); // alert('this alert is timedout and should be the first');
otherCode(); // alert("this should be the second one");
}, 5000);
I think you have to make a promise and then use a .then() so that you can chain your code together. you should look at this article https://developers.google.com/web/fundamentals/primers/promises
You could attempt to replace window.setTimeout with your own function, like so
window.setTimeout = function(func, timeout) {
func();
}
Which may or may not work properly at all. Besides this, your only option would be to change the original code (which you said you couldn't do)
Bear in mind, changing native functions like this is not exactly a very optimal approach.