Loops are fundamental constructs in programming that allow you to execute a block of code multiple times. In Ruby, there are several types of loops, each suited for different scenarios. This section will cover the following types of loops:

1. while loop
2. until loop
3. for loop
4. times loop
5. each loop

The while loop continues to execute a block of code as long as a specified condition is true.

• The loop starts with i equal to 0.
• The condition i < 5 is checked before each iteration.
• The loop prints the value of i and then increments it by 1.
• The loop stops when i reaches 5.

The until loop is the opposite of the while loop. It continues to execute a block of code as long as a specified condition is false.

• The loop starts with i equal to 0.
• The condition i == 5 is checked before each iteration.
• The loop prints the value of i and then increments it by 1.
• The loop stops when i equals 5.

The for loop iterates over a range or an array.

• The loop iterates over the range 0..4.
• For each value in the range, the loop prints the value of i.

The times loop executes a block of code a specified number of times.

• The loop executes 5 times.
• The block variable i starts at 0 and increments by 1 each time the block is executed.

The each loop iterates over each element in a collection, such as an array or a hash.

• The loop iterates over each element in the array [1, 2, 3, 4, 5].
• For each element, the loop prints the value of i.

Write a while loop that prints the numbers from 10 to 1.

Solution

Write an until loop that prints the numbers from 1 to 10.

Solution

Write a for loop that prints the even numbers from 2 to 10.

Solution

Write a times loop that prints "Hello, World!" 3 times.

Solution

Write an each loop that iterates over an array of names and prints each name.

Solution

• Infinite Loops: Ensure that the loop condition will eventually become false. For example, forgetting to increment the loop variable in a while loop can cause an infinite loop.
• Off-by-One Errors: Be careful with the range in for loops and the loop conditions in while and until loops to avoid off-by-one errors.
• Using the Correct Loop: Choose the loop that best fits the task. For example, use each for iterating over collections and times for a fixed number of iterations.

In this section, you learned about different types of loops in Ruby, including while, until, for, times, and each loops. Each type of loop has its own use cases and advantages. By practicing the provided exercises, you can reinforce your understanding and become proficient in using loops in Ruby. In the next section, we will explore methods in Ruby, which will help you write reusable and organized code.