Hash Demo Advanced: Credit Card

#Using Symbols as keys

customer = { 
  name: "Billy Bob", 
  tel: "(415)555-5555", 
}


customer['name']

customer.keys.each do |key| puts key.object_id end

customer.delete_if {| key, value | :tel == key }



hsh.compare_by_identity Use object ids instead of equality for lookups
hsh.default Returns the default value that would be used
hsh.default= Sets the default value
hsh.default_proc Returns the proc to be executed on failing lookup
hsh.default_proc= Assigns a  default proc
hsh.default_proc= proc do |hash,key| "default for #{key}" end



delete(key) {| key | block } → value