Decrement array length in Javascript

Question

I just ran across this javascript snippet:

myArray.length--;

What does it do exactly?

Answer 1

This removes the last items in the array.

var myArray = [1, 2, 3];
myArray.length--;
alert(myArray);

The output is:

[1, 2]

Answer 2

Simple experimentation shows that it chops off last element of the array.

> var a = [1, 2, 3];
=> undefined
> a
=> [1, 2, 3]
> a.length--
=> 3
> a
=> [1, 2]