Question

I already have an Hash map of school which has key as student’s first name. I would like to extract all information and create hash map with student’s School_ID as primary key.
I am getting error

undefined local variable or method ‘key1’ for main:object

key1 = Array.new
array2 = Array.new

def print_info(school_hash)         
  school_hash.each do |student|     #school_hash  has key as first name
                                    #student[0] contains First Name student[1] all info
    key1.push(student[1].School_ID) #save school_id separately to use as a key
    array2.push(student[1])         # all infos including Address, Grade, School_ID, Sports
  end
  new_hash = Hash[key1.zip(array2)]
  printf("%s",new_hash)
end

Answer 1

Move key1 and array2 into the def block or pass them in as parameters. Ruby def blocks are not closures — they cannot access local variables defined outside of them.