nil, empty and blank in Ruby

1. Use the nil Keyword in Ruby
2. Use the empty Keyword in Ruby
3. Use the blank Keyword in Ruby

Sometimes we need to confirm whether the array is empty or filled with data. Or we may need to know the properties of the array.

In Ruby, there are some keywords available for this purpose.

In this article, we will see the use of nil, empty, and blank in Ruby and some examples to make the topic easier.

The keyword nil, empty, and blank are the built-in keywords that can be used for this purpose. Let’s discuss them in detail.

Use the nil Keyword in Ruby

nil is similar to null in other programming languages. The keyword nil means nothing or there is some absence.

By using the keyword nil, you can check whether a value is nil.

In our example below, we will see how we can use the nil keyword in Ruby. Let’s take a look at the below example code.

array = [1, 2, 3, 4, 5]
puts array[5].nil?

Now the program above will show you the below output.

true

Use the empty Keyword in Ruby

empty is a built-in keyword in Ruby that allows you to check an array if it’s empty.

In our example below, we will see the use of empty. Look at the below example code.

puts [1, 2, 3].empty?
puts [].empty?

Now the program above will show you the below output.

false
true

Use the blank Keyword in Ruby

blank is a built-in keyword in Ruby that allows you to check an array if it’s blank. It is mostly similar to empty.

In our example below, we will see the use of blank. Look at the below example code.

puts [].blank?

Now the program above will show you the below output.

true

The keyword nil is used in objects, and it will return true if the object is nil, whereas empty is mainly used on strings, hashes, and arrays, and it will return true if the length of the string or array or hash is 0. And the blank is similar to empty; the only difference is that it is implemented by Ruby Rails.