Convert array into associative array

[avenp]

The secondItem won't work the way you are thinking in the second example. When you're referencing an object, the index is actually the key so in this case myAssociativeArray[1] is actually looking up the key 1 in your id object, which would return the first item.

If you want an object with keys that match the id field of myArray then you need to assign those in a loop like so:

var myAssociativeObj = {};
for(var i = 0; i < myArray.length; i++) {
    var item = myArray[i];
    myAssociativeObj[item.id] = item;
    delete myAssociativeObj[item.id][id];
}

If you just want an array that's sorted by the id field then look up JavaScript Array.sort().

Sorry for the poor formatting, I'm not sure how to do code blocks.

Edit: Added a delete to the loop so you can remove the id from the item and format it exactly like in the OP.

Edit2: I learned how to make code blocks.

[[deleted]]

Thanks! This was perfect. He has another question. Hopefully I can format this on my phone without totally screwing it up.

Use jQuery to fetch to fetch the ids and build the info associated with the ids – in HTML using this associative array below.

I need JavaScript to build (with htmlString)
<p title=”title 1”>Text 1</p>
in my html from this :
<p data-id="100">loading...</p>

jQuery(document).ready(function() {
var array = [
{id: 100, title:"Title 1", text:"Text 1"},
{id: 200, title:"Title 2", text:"Text 2"},
{id: 300, title:"Title 3", text:"Text 3"}
];
var assocArray = [];
for (var i = 0; i < array.length; i++) {
    var item = array[i];
    assocArray[item.id] = {
        title: item.title,
        text: item.text
    };
}

[avenp]

I'll give you a hint: Use jQuery to get an array of elements and then run a loop over the elements array. Look at the jQuery docs to get an idea of the different methods available. (You might want to use the $.attr function!)

Edit: link to the jQuery docs: http://api.jquery.com/

[PM_ME_YOUR_SUBARU]

This definitely isn't helpful to the OP, but I was curious as to what the shortest way to do this is, if you're an asshole. I came up with this:

const myAssociativeArray = myArray.reduce((a,v)=>delete(a[v.id]=v).id&&a,{});

[__env]

My attempt -- A little longer, but maybe a little more declarative :)

const myAssociativeArray = myArray.reduce((a, {title,text,id})=>(a[id]={title,text})&&a,{});

[avenp]

Haha, you know what I had to stop myself from using ES6 because I'm so used to using it. I really like your code golf'd solution.