Exploring present, presence and empty method in Ruby.

present Method:

present? is a method provided by ActiveSupport, an extension to the Ruby core library.

It is commonly used to check if an object is not nil and not empty.

It returns true if the object has a value (not nil and not empty), or false otherwise.

str = "Hello, World!"
puts str.present?  # Output: true

arr = []
puts arr.present?  # Output: false

num = 0
puts num.present?  # Output: true

nil_obj = nil
puts nil_obj.present?  # Output: false

presence Method:

presence is also a method provided by ActiveSupport.

It is used to return the object itself if it is present (not nil or empty), and nil otherwise.

This method is particularly useful when you want to return a default value or perform a fallback operation if the object is not present.

str = "Hello, World!"
puts str.presence  # Output: "Hello, World!"

arr = []
puts arr.presence  # Output: nil

num = 0
puts num.presence  # Output: 0

nil_obj = nil
puts nil_obj.presence  # Output: nil

empty Method:

empty? is a built-in Ruby method available on certain objects such as strings, arrays, and hashes.

It is used to check if an object is empty, meaning it has no elements or has a length of zero.

The behavior of the empty? method varies depending on the object type.

str = "Hello, World!"
puts str.empty?  # Output: false

arr = []
puts arr.empty?  # Output: true

hash = {}
puts hash.empty?  # Output: true