When to use an object and an array

Question

I have a situation where I have 3 different arrays with a very large number of objects. I read a lot of questions and blog posts about this, but I still don't know when to use what.

PS! My biggest problem is that I need iteration and push (perfect for arrays), and also find if exists in the array and delete (more suitable for objects). No specific order is required.

I cannot allow to have the same object in array1and array1clicked because they have to perform different actions.

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When is the best way to use an object and an array in my example? What should I replace with an object and what should remain an array? I'm sure the number of objects in it also matters, right?

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My current code is:

//Objects in arrays are literally custom {objects} with custom prototypes and html
var array1 = [ 20 objects ];
var array1clicked = [];

var array2 = [ 250 objects ];
var array2clicked = [];

var array3 = [ 50 000 objects ];
var array3clicked = [];

//Each object in arrays has event attached
objecthtml.click(function() {
    //Add to clicked array
    array1clicked.push(thisobject);
    //Remove from initial array
    var index = array1.indexOf(thisobject);
    if (index > -1) {
        array1.splice(index, 1);
    }
}
//Same with array2 and array3 objects


//Iterations on different conditions
var array1count = array1.length;
var array1clickedcount = array1clicked.length;

//Same with array2 and array3

if(condition1) {
   for(a = 0; a < array1count; a++) {
       array1[a].div.style.visibility = 'hidden';
   }
   //Same with array2 and array3 objects

   for(a = 0; a < array1clickedcount; a++) {
       array1clicked[a].div.style.visibility = 'visible';
   }
   //Same with array2clicked and array3clicked objects
}
else if(condition2) {
   for(a = 0; a < array1count; a++) {
       array1[a].div.style.visibility = 'visible';
   }
   //Same with array2 and array3 objects

   for(a = 0; a < array1clickedcount; a++) {
       array1clicked[a].div.style.visibility = 'hidden';
   }
   //Same with array2clicked and array3clicked objects
}

Answer 1

It seems you need a data structure with these operations:

• Iteration
• Embed
• Delete
• Search

With arrays, the problem is that finding and deleting (with reindexing) is slower.

The problem with objects is that property names can only be strings.

The ideal structure is a set.

var s = new Set();
s.add(123); // insert
s.has(123); // search
s.delete(123); // delete
s.values(); // iterator

Answer 2

In your case, I think you only need to use Array.

, , , Array.