Tutorial by Examples

MY_CONSTANT = "Hello, world" # constant Constant = 'This is also constant' # constant my_variable = "Hello, venus" # not constatn Constant name start with capital letter. Everything that start with capital letter are considered as constant in Ruby. So class and module are al...

MY_CONSTANT = "Hello, world" MY_CONSTANT = "Hullo, world" The above code results in a warning, because you should be using variables if you want to change their values. However it is possible to change one letter at a time in a constant without a warning, like this: MY_CONST...

def say_hi MESSAGE = "Hello" puts MESSAGE end The above code results in an error: SyntaxError: (irb):2: dynamic constant assignment.

class Message DEFAULT_MESSAGE = "Hello, world" def speak(message = nil) if message puts message else puts DEFAULT_MESSAGE end end end The constant DEFAULT_MESSAGE can be changed with the following code: Message::DEFAULT_MESSAGE = "Hullo, wo...