Question

I found that << can not be used by Array unless it has already been initialized. I currently write it like this:

unless @app
 @app = my_array
else
 @app << my_array
end 

Is there a better way to write this?

I used ||= before, but

(@app ||= []) << [1,2,3]

will return [[1, 2, 3]], that’s not we want. We want [1, 2, 3]

Answer 1

perhaps you are using << wrong? << is meant for an element of the array, not a chunk of an array.

@app ||= []
@app.concat my_array