So, a lot of people are answering with pop(), but most of them don't seem to realize that's a destructive method.

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

So, for a really silly, nondestructive method:

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

a push pop, like in the 90s :)

push appends a value to the end of an array, and returns the length of the result. so

d=[] d.push('life') //=> 1 d //=>['life'] 

pop returns the value of the last item of an array, prior to it removing that value at that index. so

c = [1,2,1] c.pop() //=> 1 c //=> [1,2] 

arrays are 0 indexed, so c.length => 3, c[c.length] => undefined (because you're looking for the 4th value if you do that).

So, a lot of people are answering with pop(), but most of them don't seem to realize that's a destructive method.

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

So, for a really silly, nondestructive method:

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

a push pop, like in the 90s :)

push appends a value to the end of an array, and returns the length of the result. so

d=[] d.push('life') //=> 1 d //=>['life'] 

pop returns the value of the last item of an array, prior to it removing that value at that index. so

c = [1,2,1] c.pop() //=> 1 c //=> [1,2] 

arrays are 0 indexed, so c.length => 3, c[c.length] => undefined (because you're looking for the 4th value if you do that(this level of depth is for any hapless newbs that end up here)).

Probably not the best, or even a good method for your application, what with traffic, churn, blah. but for traversing down an array, streaming it onto another, just being silly with inefficient methods, this. Totally this.