Must yield this collection's elements to the block.

Returns true if self does not contain any element.

([] of Int32).empty? # => true
([1]).empty?         # => false
[nil, false].empty?  # => false

• #present? returns the inverse.

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

Pretty prints self into the given printer.

By default appends a text that is the result of invoking #inspect on self. Subclasses should override for custom pretty printing.

Appends a short String representation of this object which includes its class name and its object address.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).to_s # => #<Person:0x10a199f20>