Why do Ruby think this is a symbol

Ruby
#1

Hello,

I have this script:

def solution(keys, default_value)
answer = Hash.new(default_value)
keys.each { |k| answer.add k }
end

and this test file :

Test.assert_equals( {:draft => 0, :completed => 0}, solution([:draft,
:completed], 0))

But now I see this error message :

NoMethodError: undefined method `add’ for {}:Hash

Roelof

#2

Your calling .add on answer (which is a hash) within your each block.

.add is a method for Set not Hash.
http://www.ruby-doc.org/stdlib-1.9.3/libdoc/set/rdoc/Set.html

What are you trying to accomplish with this method??

Todd Pickell
Software Developer & Consultant

On May 30, 2014 at 3:46:42 PM, Roelof W. ([email protected]) wrote:

Hello,

I have this script:

def solution(keys, default_value)
answer = Hash.new(default_value)
keys.each { |k| answer.add k }
end

and this test file :

Test.assert_equals( {:draft => 0, :completed => 0}, solution([:draft,
:completed], 0))

But now I see this error message :

NoMethodError: undefined method `add’ for {}:Hash

Roelof

#3

There is no method Hash#add() , does not exist. What you want to
acomplish I think is this:

def solution(keys, default_value)
answer = Hash.new(default_value)
keys.each { |k| answer[add] = default_value }
end

Try to refer to the documentation. If you have Ruby installed in
Windows by Ruby Installer you should have a folder with a *.chm file
with documentation. Other way there is the online Ruby API
documentation, google it.

#4

ups was wrong

#5

Damián M. González wrote in post #1147846:

There is no method Hash#add() , does not exist. What you want to
acomplish I think is this:

def solution(keys, default_value)
answer = Hash.new(default_value)
keys.each { |k| answer[add] = default_value }
end

I am not sure this is what OP wants. I’d rather guess (notice the usage
of “k”):

def solution(keys, default_value)
answer = Hash.new(default_value)
keys.each { |k| answer[k] = default_value }
end

But that does not make sense because the whole point of the default
value of a Hash is that the key does not need to be there to return the
default value when queried.

There also seems a more fundamental issue: “answer” goes nowhere, it is
not returned. But if one takes these two points together, then there is
really nothing left which justifies a method:

def solution(keys, default_value)
Hash.new(default_value)
end

That method is basically superfluous and can be replaced by the single
line it contains.

So, Roelof, what do you want to achieve?

#6

I am not sure this is what OP wants. I’d rather guess (notice the usage
of “k”):

def solution(keys, default_value)
answer = Hash.new(default_value)
keys.each { |k| answer[k] = default_value }
end

Yes Robert, was my fault, did it quickly, thanks for correct.