Is it possible to stop an infinite loop from running at all?
Right now I am doing something like this:
var run = true;
loop ({
if(run) {
whatever
}
}, 30),
Then when I want to stop it I change run to false, and to true when I want to start it again.
But the loop is always running whatever I do. It just not executing the code inside.
Is there a way to stop it completely? and make it start again when I want?
If I am understanding your question correctly, what you need is the break keyword. Here's an example.
SetInterval will give you a loop you can cancel.
setInterval ( "doSomething()", 5000 );
function doSomething ( )
{
// (do something here)
}
Set the interval to a small value and use clearinterval to cancel it
function infiniteLoop() {
run=true;
while(run==true) {
//Do stuff
if(change_happened) {
run=false;
}
}
}
infiniteLoop();
It may not be exactly what you are looking for, but you could try setInterval.
var intervalId = setInterval(myFunc, 0);
function myFun() {
if(condition) {
clearInverval(intervalId);
}
...
}
setInterval will also not block the page. You clear the interval as shown with clearInterval.
Use a while loop
while(run){
//loop guts
}
When run is false the loop exits. Put it in a function and call it when you want to begin the loop again.
The problem is that javascript only has a single thread to run on. This means that while you are infinitely looping nothing else can happen. As a result, it's impossible for your variable to ever change.
One solution to this is to use setTimeout to loop with a very small time passed to it. For example:
function doStuff(){
if(someFlag){
// do something
}
setTimeout(doStuff,1);
}
doStuff();
This will give the possibility for other actions to make use of the thread and potentially change the flag.
loopa function?forandwhilewithbreak,setTimeoutwith flag,setIntervalwithclearInterval.