This question already has answers here:
How to access the correct `this` inside a callback
(13 answers)
Closed 8 years ago.
Im trying to use setTimeout() for a recursive function, inside a method. I'm assuming I'm getting something with the 'this' scope wrong though. Here's an example.
(function(scope){
function gamePlay(){
// this.initialize();
}
gamePlay.prototype.droidMovement = function(){
console.log('droid is moving');
this.droidShoot();
}
gamePlay.prototype.droidShoot = function(){
console.log('droidShoot() has been fired');
setTimeout(this.droidShoot,1000);
}
scope.gamePlay = gamePlay;
})(window);
var game = new gamePlay();
game.droidMovement();
Ive tried the setTimeout 3 ways.
//this way repeats the function 2 times then stops
setTimeout(this.droidShoot,1000);
//this gives me an error
setTimeout(function(){this.droidShoot()},1000);
//this fires the function in a loop but doesnt wait the second
setTimeout(this.droidShoot(),1000);
Can anyone please explain what I'm doing wrong? thanks so much in advance.
You may want to remove the setTimeout from within the definition of droidShoot and replace setTimeout(this.droidShoot, 1000) with setInterval(this.droidShoot, 1000.
setInterval will automatically call this.droidShoot repeatedly at a 1s interval
Related
This question already has answers here:
Are variables statically or dynamically "scoped" in javascript?
(7 answers)
What is the scope of variables in JavaScript?
(27 answers)
Closed 2 years ago.
I am looking for someone to explain me something since I can't find a clear answer. My question is about functions that call themselves. I saw that it is possible to build a list of functions that are 'chained' together and for example the first function calls the second one then the second one calls another one. My confusion is : Lets say that you have a second function that has a variable let a = 12; if i call that function on the first function, will i have access to that variable or whatever that second function might have inside? How can i pass info to another function? can a function can be dependent on another function in order to complete a task? Thanks in advance guys.
Edit to make it more clear what I mean:
function first(){
second();
// will i have access to whatever there is inside function second since i am calling it here ? or it doesn't work that way?
}
function second(){
let a = 12;
third();
}
function third(){
fourth()....
}
This question already has answers here:
What is the difference between a function call and function reference?
(6 answers)
Closed 2 years ago.
Recently I started learning about JS, and I got stuck in the following issue:
I am trying to call a function "draw_point" when a "mousemove" event happens.
When trying the following, the code works as expected (the function gets called):
svg.on('mousemove', draw_point(true));
But when replacing the caller function like this, it stops working and I don't get any error messages to troubelshoot.
svg.on('mousemove', function () {
draw_point;
});
Any explanation of what is going on?
Both examples are wrong, but for different reasons. In the first, you're calling the functiondraw_point immediately and passing its return value to the .on call. In the second, you're creating an anonymous function that wraps draw_point, but you're not calling draw_point. This is legal because javascript allows empty statements like myVar; or 3;.
What you want to do is pass the function draw_point, but not call it. It will be called when the handler runs:
svg.on('mousemove', draw_point);
This question already has answers here:
JavaScript setTimeout() won't wait to Execute? [duplicate]
(3 answers)
Closed 4 years ago.
I want to make a function being called in a certain interval of time inside the constructor. But I don't want to write the function inside the $interval statement because it's a little big. So I wanted to make something like this:
this.$interval(this.getSomething(), 1000);
And the initialize it outside of the controller's constructor:
getSomething = function getSomething(){
...
};
But it gives me an error of
TypeError: fn is not a function When it seems to me as a function... Any suggestions?
Try changing your function declaration to this.
getSomething = function(){
...
};
and call your interval part like this.
this.$interval(function(){ this.getSomething() }, 1000);
This question already has answers here:
Why is the method executed immediately when I use setTimeout?
(8 answers)
Closed 5 years ago.
Problem: Hello i'm a little stuck as to why setTimeout() does not call the function specified after the time passed I've tried a few things but nothing seems to work
Solution: If anyone knows any other way to call a function after a specific time
Here is my code :
refreshStats: function(){
this.goldLabel.text = Math.floor(this.player.data.gold);
this.attackLabel.text = Math.floor(this.player.data.attack);
this.defenseLabel.text = Math.floor(this.player.data.defense);
if (this.player.questsDone.length > 0){
console.log(this.player.questsDone)
this.bpText.text = this.player.questsDone[this.player.questsDone.length-1];
setTimeout(this.FadeConsoleText(), 5000);
}
},
FadeConsoleText: function(){
console.log("log");
},
Current output:
"Quest"
"a"
wanted Solution output:
"Quest"
(wait then call function)
"a"
Thank you in advanced
You want to pass the function, not what the function returns to setTimeout:
setTimeout(this.FadeConsoleText, 5000);
This question already has answers here:
Why is my function call that should be scheduled by setTimeout executed immediately? [duplicate]
(3 answers)
Closed 7 years ago.
I'm trying to call a function every x-seconds,
setInterval( alert("Hello"),2000);
But the alert function appear just for the first call,
You may try this:
setInterval(function() {
alert("Hello");
} ,2000);
It's not working like you thought. The alert fires/runs directly without interval because you've directly called it. To be more clerer, in your code:
setInterval(alert("Hello"),2000);
You are calling the alert("Hello") but you should pass a function (or bind) which you want to run on an interval, which is:
setInterval(function(){
// ...
}, 2000);
So the passed anonymous function will be called using the given interval (bind is another way but I've used a function/closure for simplicity to clarify you).