Create array of objects Javascript

Question

I created this Object with 3 properties:

Node = {
 name : "",
 isOkay : true,
 rotation : 0.0
}; 

How would i go creating an array of these objects, in size of 100.

So later i could do something like this:

nodeList[74].name = "Peter";
nodeList[74].isOkay = false;
nodeList[74].rotation = 1.3;

or similar...

I'm really new to this, i found couple of topics about this, but it never compiles properly.

I would be really grateful if anyone could show the proper syntax, Thanks!

• Felix Kling: You could read a tutorial (or two) to learn the basics about arrays. If you already tried something but are having troubles with it, then please post your code!
• 最白目: Be careful with terminology: Javascript code isn´t compiled, it´s interpreted.
• Felix Kling: @dan: I believe Chrome does JIT-compilation.
• Andrew Koper: Your question is ambiguous. You're using literal notation to create your object and get properties from it. One way to do what you want to do is to do that 300 times. What format is the data currently in? That would allow an experienced developer to write the code to transform it into an array of objects.

Answer 1

I would use this way:

var Node = function() {
 this.name = "";
 this.isOkay = true;
 this.rotation = 0.0
}
var nodeList = [];
for (var i = 0; i < 10; i++) 
{ 
 nodeList.push(new Node()); 
}
nodeList[0].name = "test";

So you could create a new object(really new) in order to manage it later. Look here.

EDIT:

What I have done is created an object with a constructor method, you can check it on MDN here.

Creating an object like you have done:

var Node = { /* ... */ }

Is like having one object initiated. To have another, you'll have to write another one and so on. With that contructor you may create any instances you want based on that model.

• JohnPeterson: Thank you very, very much ! :) I am more of a non-web c# software programmer, web based applications in javascript gives me a bit of the headache. Could you please say, why this.name is your better suggested than just my "name"? Thanks again
• DontVoteMeDown: @JohnPeterson look my edit. And thank you, Some day you come back and upvote it ;) haha glad to help.

Answer 2

You might want to do this lazily

Depending on the situation might be helpful to do this lazily

var Node = function(name, isOkay,rotation){
 if(!(this instanceof Node)) return new Node(name,isOkay,rotation);
 else {
 this.name = name;
 this.isOkay = isOkay;
 this.rotation = rotation;
 }
}
var NodeCollective = function(numberOfNodes){
 if(!(this instanceof NodeCollective)) return new NodeCollective(numberOfNodes);
 else{
 var _collective={};
 var _defaultName = "", _defaultIsOkay = true, _defaultRotation=0.0;
 this.length = numberOfNodes;
 this.getNode=function(nodeNumber){
 if(!_collective.hasOwnProperty(nodeNumber) && nodeNumber < numberOfNodes){
 _collective[nodeNumber]=
 Node(_defaultName,_defaultIsOkay,_defaultRotation);
 }
 //I am just assuming I am not going to get garbage
 //you can put in checks to make sure everything is kosher
 //if you really want to
 return _collective[nodeNumber];
 };
 }
}

but it also depends on what you are trying to do... if you might not be getting all of the nodes in your program then implementing them in some way that avoids greedily creating them could save you a lot of time if the code is executed often, but if the piece of code isn't executed often this might be over kill.

Answer 3

var nodeList = []; // create empty array
nodeList.push(Node); // add the object to the end of the array
nodeList[0].rotation = 1.3; // set rotation property of the object
console.log(nodeList[0]); // prints the object to console

• DontVoteMeDown: This will create a reference for each element in the array, look this fiddle.
• tylerargo: That's a good thing to note but I wasn't saying he should loop adding the same node. I was explaining how to add a single node to an array and hoping he could take it from there himself to add more.
• tylerargo: Yes it is and if he wants to add more he'll have to use the literal notation to create more and add them or do something smarter like your answer.
• tylerargo: I hope you aren't misunderstanding me. Your way really is better than mine :P