In previous lessons, you've learned the basics of for and each loops as well as loop controls like break and next in Ruby. Now, it’s time to dive deeper into other important loop structures: while and until loops. Understanding these loops will provide you with more tools to handle different programming challenges effectively.

In this lesson, you'll explore how to use while and until loops to perform repetitive tasks based on conditions. With while loops, the code will run as long as a specified condition is true. Conversely, until loops will execute as long as a condition is false.

Let's examine some code examples to understand these concepts:

Ruby
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1budget = 1200
2spent = 0
3
4amount = 250
5
6# The condition checks if we can spend the amount without exceeding the budget limit
7# The loop will run as long as the spent amount plus the new amount is less than or equal to the budget
8while spent + amount <= budget
9    # If the condition is true, we update the spent amount and print the total spent so far
10    spent += amount
11    puts "Spent #{spent} so far"
12end
13
14puts "Budget is now #{budget - spent}"

After exhausting the budget with a while loop, you might perform a similar task using an until loop:

Ruby
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1budget = 1200
2spent = 0
3
4amount = 250
5
6# The condition checks if we can spend the amount without exceeding the budget limit
7# The loop will run until the spent amount plus the new amount exceeds the budget
8until spent + amount > budget
9    # If the condition is false, we update the spent amount and print the total spent so far
10    spent += amount
11    puts "Spent #{spent} so far"
12end
13
14puts "Budget is now #{budget - spent}"

Mastering while and until loops is essential for writing efficient and robust Ruby programs. These loops allow you to:

• Automate repetitive tasks: Handle operations that need to occur multiple times until a specific condition changes.
• Write more readable and maintainable code: Choosing the right loop structure can make your intentions clearer, leading to cleaner and more understandable code.

By the end of this lesson, you'll have a solid understanding of when and how to use while and until loops. This will enable you to tackle a variety of programming challenges more effectively.

Let's get started and explore these loops in depth!