- default
Function parameter default value
examples/functions/default_value.cr
def welcome(name = "World") return "Hello #{name}!" end puts welcome puts welcome("Foo")
Hello World! Hello Foo!
- Type definition for parameters
examples/functions/parameter_types.cr
def welcome(name : String) return "Hello #{name}" end puts welcome "Foo" # puts welcome 42 # Error: no overload matches 'welcome' with type Int32 def add(x, y : Int32) puts "#{x} #{y}" end add(2, 3) # add(2, 3.1) # Error: no overload matches 'add' with types Int32, Float64 add(2.1, 3) # this works