How to Use the Unless Statement in Ruby

09/21/2021

Contents

In this article, you will learn how to use the unless statement in Ruby.

The Unless Statement

In Ruby, the unless statement is used to execute a block of code if a condition is false. Here’s the basic syntax of an unless statement in Ruby:

unless condition
  # code to be executed if the condition is false
end

Alternatively, you can use the one-liner syntax, which is useful for simple conditions:

# code to be executed unless the condition is true
code unless condition

Here’s an example of how to use unless in Ruby:

x = 10

unless x > 20
  puts "x is not greater than 20"
end

# Output: "x is not greater than 20"

In the above example, the block of code is executed because the condition x > 20 is false.

You can also use else and elsif statements with unless to handle other conditions. Here’s an example:

x = 5

unless x > 10
  puts "x is not greater than 10"
elsif x > 5
  puts "x is greater than 5"
else
  puts "x is less than or equal to 5"
end

# Output: "x is less than or equal to 5"

In the above example, the first condition x > 10 is false, so the code inside the unless block is executed. Since there is an elsif statement, the program checks the next condition x > 5. This condition is also false, so the code inside the else block is executed, which prints “x is less than or equal to 5”.

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