jQuery equivalent to Prototype array.last()

Question

Prototype:

var array = [1,2,3,4];
var lastEl = array.last();

Anything similar to this in jQuery?

Answer 1

Why not just use simple javascript?

var array=[1,2,3,4];
var lastEl = array[array.length-1];

You can write it as a method too, if you like (assuming prototype has not been included on your page):

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

Answer 2

with slice():

var a = [1,2,3,4];
var lastEl = a.slice(-1)[0]; // 4
// a is still [1,2,3,4]

with pop();

var a = [1,2,3,4];
var lastEl = a.pop(); // 4
// a is now [1,2,3]

see https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array for more information

Answer 3

When dealing with a jQuery object, .last() will do just that, filter the matched elements to only the last one in the set.

Of course, you can wrap a native array with jQuery leading to this:

var a = [1,2,3,4];
var lastEl = $(a).last()[0];

Answer 4

Why not use the get function?

var a = [1,2,3,4];
var last = $(a).get(-1);

http://api.jquery.com/get/ More info

Edit: As pointed out by DelightedD0D, this isn't the correct function to use as per jQuery's docs but it does still provide the correct results. I recommend using Salty's answer to keep your code correct.

Answer 5

I know the answer is already given, but I think I've got another solution for this. You could take the array, reverse it and output the first array item like this:

var a = [1,2,3,4];
var lastItem = a.reverse()[0];

Works fine for me.

Answer 6

For arrays, you could simply retrieve the last element position with array.length - 1:

var a = [1,2,3,4];

var lastEl = a[a.length-1]; // 4

In jQuery you have the :last selector, but this won't help you on plain arrays.

Answer 7

If u use the prototype on arrays like:

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

using forloops will do this.

var a = [0,1,2];
out --> 0
out --> 1
out --> 2
out --> last

Answer 8

According to jsPerf: Last item method, the most performant method is array[array.length-1]. The graph is displaying operations per second, not time per operation.

It is common (but wrong) for developers to think the performance of a single operation matters. It does not. Performance only matters when you're doing LOTS of the same operation. In that case, using a static value (length) to access a specific index (length-1) is fastest, and it's not even close.

Answer 9

You can use this Arr.slice(-1)[0].

Arr=[1,2,3,4,5,6,7]

Lets understand this. -1 means you are looking last index of Array. so when you use Arr.slice(-1)[0] then you will get result : 7.

Answer 10

See these test cases http://jsperf.com/last-item-method The most effective way is throug .pop method (in V8), but loses the last element of the array

Answer 11

url : www.mydomain.com/user1/1234

$.params = window.location.href.split("/"); $.params[$.params.length-1];

You can split based on your query string separator

Answer 12

SugarJS

It's not jQuery but another library you may find useful in addition to jQuery: Try SugarJS.

Sugar is a Javascript library that extends native objects with helpful methods. It is designed to be intuitive, unobtrusive, and let you do more with less code.

With SugarJS, you can do:

[1,2,3,4].last()    //  => 4

That means, your example does work out of the box:

var array = [1,2,3,4];
var lastEl = array.last();    //  => 4

More Info

• SugarJS Homepage
• Feature Overview
• All about arrays in SugarJS

Answer 13

I use this:

array.reverse()[0]

You reverse the array with reverse() and then pick the first item of the reversed version with [0], that is the last one of the original array.

You can use this code if you don't care that the array gets reversed of course, because it will remain so.