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

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.