CODEWITHSUNDEEP
ruby
user2134050
user2134050

Reputation: 107

Ruby Pointers/Reference

require 'csv'

class Apple
    def initialize()
        @num = CSV.read("Location", :headers=>false)
        #assume @num[0][0] has 'A1D'
    end
    def Display()
        puts @num[0][0]
    end
    def Problem()
        temp = @num[0][0]
        temp['D'] = "A"
    end
end

ap = Apple.new
ap.Display
ap.Problem
ap.Display

Displayed answer A1D A1A

When you assign temp to @num[0][0], I don't want any changes happening in @num when I make changes in temp value.

I am not sure how to do this. Please help.

Upvotes: 0

Views: 30

Answers (2)

Chuck
Chuck

Reputation: 237060

If you don't want to mutate the original object, you need to make a copy (say, by dup). Remember, though, that any instance variables in the dup'ed object will still reference the same objects they did in the original, so you'll need to dup those as well if you want to modify them.

Upvotes: 1

Arup Rakshit
Arup Rakshit

Reputation: 118271

You need to use just temp = @num[0][0].dup. As you did temp = @num[0][0], thus temp is pointing to the object, which is @num[0][0] giving. Thus any change to the string object pointed by temp will affect the string lies in @num[0][0].

Upvotes: 2

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