Ruby Block

Updated April 10, 2023

Introduction to Ruby Block

Block in Ruby is a similar concept like any method. Ruby block allows us to use all calculations and manipulation in the same way how we perform inside any method. So we can say blocks in Ruby are similar to any method, but blocks does not belongs to any objects, broadly we can say that there could be three types of block in Ruby first block with do and end, block with inline (basically a block with curly braces ) and a block which can get some argument with help of the pipe symbol(||), all these types of blocks will be used to do some calculation and manipulation (addition, changing data or any arithmetic operations).

Syntax of ruby block:

We can divide the syntax for blocks in Ruby in three sections.

• Writing block within the do and end statement. In the below syntax we have created a block with the name name_of_block, here this block contains some code statement which will be executed.

name_of_block do
#code statement 1
#code statement 2
#code statement 3
…
...
end

• Writing block with help of curly braces. In this syntax block we have created a block with name name_of_block and within this we have created a block with curly braces which contains some codes for executions.

name_of_block{ #list of statement which is going to be executed }

• A block where we can also pass some arguments. To pass argument to block we can use the || symbol which allows us to pass the argument blocks.

How do Blocks work in Ruby?

Ruby Block plays a very vital role in handling various manipulations and it is a substitute for methods in Ruby. Many people are not comfortable for writing block in Ruby they preferred to write method instead of writing block. With help of block code we will be able to reduce the code size.

Given below is the working of the block in the following steps:

• Any block is similar to the closure of other programming languages.
• Biggest advantage of using block is it can get any number of arguments and return a value.
• Block also performs tasks in the same way how methods work. For example in block we can do addition and any arithmetic operations.
• Every block is made of code chunks, which means it contains the chunks of the codes which are performing a separate activity.
• An important thing about the block is it will always call by any method or we can pass it to any other method.
• In case if we wanted to use the block inside any method then we should use yield keyword.
• If we want we can make a call to the block inside any method, here block is passed to method while calling a method.

In Ruby we can have three different types:

1. With help of the do and end statement: This is the most common approach to create any block in Ruby. We can write some repetition code with help of do and get each attribute of it.
2. Block with curly braces or by using inline blocks: We can use the curly braces for creating any block in Ruby, inside the curly braces we can write the codes or codes for compilation of certain task blocks.
3. Block with arguments: We can pass some arguments to the block with help of the || symbol .

["Ranjan", "Ajay", "Vijay","Suresh"].each do |name|
puts name
end

["Ranjan", "Ajay", "Vijay","Suresh"].each {|name| puts name}

students = ["Ranjan", "Ajay", "Vijay","Suresh","Anjali","Alka","Priya","Vivek","Suresh","Nikita","Krishna","Jaya"]
students.each do |students|
puts students
end

puts [22, 21, 19, 11, 51,31].select { |number| number.odd? }