javascript - (Deep) copying an array using jQuery

I need to copy an (ordered, not associative) array of objects. I'm using jQuery. I initially tried

jquery.extend({}, myArray)

but, naturally, this gives me back an object, where I need an array (really love jquery.extend, by the way).

So, what's the best way to copy an array?

Answer

Since Array.slice() does not do deep copying, it is not suitable for multidimensional arrays:

var a =[[1], [2], [3]];
var b = a.slice();

b.shift().shift();

// a is now [[], [2], [3]]

Note that although I've used shift().shift() above, the point is just that b[0][0] contains a pointer to a[0][0] rather than a value.

Likewise delete(b[0][0]) also causes a[0][0] to be deleted and b[0][0]=99 also changes the value of a[0][0] to 99.

jQuery's extend method does perform a deep copy when a true value is passed as the initial argument:

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

var b = $.extend(true, [], a);

b.shift().shift();
// a is still [[1], [2], [3]]