What is the difference of Ruby's Array#to_a method -

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for example:

a = [1,2,3,4] b = c = a.to_a a.insert(0,0)  #=> [0,1,2,3,4] b              #=> [0,1,2,3,4] c              #=> [0,1,2,3,4]

why output of array b , c same? if want copy of array a, not reference one, method should use?

you can 

b = a.dup

old post
can try if there no easier way

b = a.map {|x| x}

it works

1.9.3-p448 :001 > = [1,2,3]      => [1, 2, 3]  1.9.3-p448 :002 > b =            => [1, 2, 3]  1.9.3-p448 :003 > c = a.map{|x| x} => [1, 2, 3]  1.9.3-p448 :004 > a<<0             => [1, 2, 3, 0]  1.9.3-p448 :005 > b                => [1, 2, 3, 0]  1.9.3-p448 :006 > c                => [1, 2, 3]

but shallow copy though.

according this post, a.dup easier way.


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