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February 8, 2024 Ruby

Loops in Ruby: A Simple Approach

When coding in Ruby, you will find that loops are a critical tool to control the flow of your program and manipulate data effectively.

The basic purpose of a loop is to execute a block of code multiple times. Different types of loops can be used based on the specific situation at hand.

Our focus here is to simplify the various types of loops Ruby supports, how they work, and when to use each type.

The While Loop

One of the most commonly used loops in Ruby is the while loop. The while loop continues execution as long as a given condition is true. It is essential for situations where you are unsure of how many iterations are needed:


i = 0
while i < 5 do
  puts "Iteration number #{i}"
  i += 1
end
Code language: JavaScript (javascript)

The above example prints the iteration number for each loop until i is no longer less than 5.

The Until Loop

Sometimes, it might be easier to define the condition for which the loop should stop, rather than continue. In Ruby, the until loop is used in these situations. A until loop executes until a certain condition is met:


i = 0
until i >= 5 do
  puts "Iteration number #{i}"
  i += 1
end
Code language: JavaScript (javascript)

Just like the while loop example earlier, this will print the iteration number until i is no longer less than 5.

For Loop

When the exact number of iterations is known in advance, the for loop can be a useful tool. It allows you to iterate over a range of values:


for i in 0..5
  puts "Iteration number #{i}"
end
Code language: JavaScript (javascript)

This for loop example will print values from 0 to 5 inclusive.

Each Loop

Often when working with arrays or ranges, the each loop is your best friend. This loop allows easy traversal of such objects without having to handle a counter:


[1, 2, 3, 4, 5].each do |i|
  puts "Iteration number #{i}"
end
Code language: JavaScript (javascript)

In this each loop example, each element in the array is passed to the block and printed in the console.

Know Your Loops

It is important to know the strengths and weaknesses of each type of loop. The while and until loops are great for when we don’t know how many times we need to loop, and the for loop helps us when we have a definite number of iterations.

Limit Your Loops

Be mindful of the performance implications when working with loops. If you’re dealing with large data sets, using the limit can help prevent your program from becoming slow or unresponsive.

Refactor Your Loops

As your understanding of loops and the Ruby language improves, always revisit your old code to see how you could improve or optimize your loops.

Experiment with Loops

The best way to learn is by doing. So don’t be afraid to experiment with loops and try new things. You’ll likely find better ways to solve problems by pushing your comfort zone.

Wrap Up

Loops are a fundamental aspect of any programming language, and Ruby is no different.

By now, you should have a decent understanding of the different loops available in Ruby, their syntax, and when to use each for maximum code efficiency and effectiveness.

Remember that continual practice is key to mastering loops or any other programming construct for that matter. Happy coding!

Check out the previous article Hashes in Ruby.

Benji
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