Upto and downto methods in Ruby - Mini Project: Build & Apply

Using upto and downto Methods in Ruby

📖 Scenario: You are helping a teacher prepare a list of student roll numbers for attendance. The roll numbers go from 1 to 5. Then, you want to count backwards from 5 to 1 to check the order.

🎯 Goal: Build a Ruby program that uses upto to count from 1 to 5 and downto to count back from 5 to 1, printing each number.

📋 What You'll Learn

Create a variable start_num with the value 1

Create a variable end_num with the value 5

Use upto method on start_num to print numbers from 1 to 5

Use downto method on end_num to print numbers from 5 down to 1

💡 Why This Matters

🌍 Real World

Counting sequences like roll numbers, pages, or steps is common in many programs. Using <code>upto</code> and <code>downto</code> helps automate these counts easily.

💼 Career

Understanding these methods is useful for Ruby developers working on tasks involving loops, ranges, and iteration, common in web development and scripting.

1

Create the starting number variable

Create a variable called start_num and set it to 1.

Ruby

# Create a variable called start_num and set it to 1
# Your code here

Need a hint?

Use = to assign the value 1 to start_num.

2

Create the ending number variable

Create a variable called end_num and set it to 5.

Ruby

start_num = 1
# Create a variable called end_num and set it to 5
# Your code here

Need a hint?

Use = to assign the value 5 to end_num.

3

Use upto to print numbers from 1 to 5

Use the upto method on start_num with end_num to print each number from 1 to 5. Use a block with variable num and print num inside the block.

Ruby

start_num = 1
end_num = 5
# Use upto on start_num to print numbers up to end_num
# Your code here

Need a hint?

Use start_num.upto(end_num) do |num| ... end and inside the block use puts num.

4

Use downto to print numbers from 5 down to 1

Use the downto method on end_num with start_num to print each number from 5 down to 1. Use a block with variable num and print num inside the block.

Ruby

start_num = 1
end_num = 5
start_num.upto(end_num) do |num|
  puts num
end
# Use downto on end_num to print numbers down to start_num
# Your code here

Need a hint?

Use end_num.downto(start_num) do |num| ... end and inside the block use puts num.