Find the ObjectID for an array?

Chris Fullmer

I am working with some arrays and I was wondering how to find the objectID of each array? I am imagining doing something like:

puts my_array.object_id

Anything like that possible? I'm probably just overlooking the obvious...

Chris

Chris Fullmer

Oh! I found it. my_array.id gives an object id. That works. I was having problems with duplicate arrays and I was able to track them down with this. This is what the problem was.

I was creating an array full of empty arrays with this:

needed_arrays = 100 my_array = Array.new(needed_arrays, Array.new)

Apparently that makes an array with 100 identical arrays. So if you push something to my_array[0] or my_arra[99], it is all going into the same ayyar apparently....

Instead I used

my_array = [] needed_arrays = 100 needed_arrays.times { my_array << [] }

and that is working much better.

Chris

Jim

Actually, the method is .object_id

@chris fullmer said:

Apparently that makes an array with 100 identical arrays.

100 references to the same Array, but not 100 arrays. I know, I'm being pedantic.

Create them as needed:

my_array = []
my_array[index] ||= [] 
my_array[index].push(value)

Chris Fullmer

@jim said:

100 references to the same Array, but not 100 arrays. I know, I'm being pedantic.

Its ok, its good for me. And is there a difference between .object_id and .id and .id ? And I saw a hint at :name - what is that? I couldn't get it to work.

And in your example, what does ||= do? I'm guessing it creates an empty array at [index] if there is not an array there already?

Thanks Jim.

Chris