Selecting last element in JavaScript array

use es6 deconstruction array with the spread operator

var last = [...yourArray].pop();

note that yourArray doesn't change.

Use the slice() method:

my_array.slice(-1)[0]

You can also .pop off the last element. Be careful, this will change the value of the array, but that might be OK for you.

var a = [1,2,3];
a.pop(); // 3
a // [1,2]

How to access last element of an array

It looks like that:

var my_array = /* some array here */;
var last_element = my_array[my_array.length - 1];

Which in your case looks like this:

var array1 = loc['f096012e-2497-485d-8adb-7ec0b9352c52'];
var last_element = array1[array1.length - 1];

or, in longer version, without creating new variables:

loc['f096012e-2497-485d-8adb-7ec0b9352c52'][loc['f096012e-2497-485d-8adb-7ec0b9352c52'].length - 1];

How to add a method for getting it simpler

If you are a fan for creating functions/shortcuts to fulfill such tasks, the following code:

if (!Array.prototype.last){
    Array.prototype.last = function(){
        return this[this.length - 1];
    };
};

will allow you to get the last element of an array by invoking array's last() method, in your case eg.:

loc['f096012e-2497-485d-8adb-7ec0b9352c52'].last();

You can check that it works here: http://jsfiddle.net/D4NRN/