gistfile1.rb

def replace_things(string)
  string = string.gsub(/lice/, 'dam')
end

def alter_things(string)
  string.gsub!(/lice/, 'dam')
end

person = "Alice"

p person
# "Alice"

replace_things(person)
p person
# "Alice"

alter_things(person)
p person
# "Adam"