Performance profiling basics in Ruby - Mini Project: Build & Apply

Performance profiling basics

📖 Scenario: You are working on a Ruby program that processes a list of numbers. You want to understand which part of your code takes the most time so you can improve it.

🎯 Goal: Learn how to use Ruby's built-in performance profiling tools to measure how long parts of your code take to run.

📋 What You'll Learn

Create an array of numbers

Set up a variable to store the start time

Write a loop that processes the numbers

Print the total time taken to process

💡 Why This Matters

🌍 Real World

Measuring how long parts of your program take helps you find slow spots and make your code faster.

💼 Career

Performance profiling is a key skill for developers to optimize applications and improve user experience.

1

Create an array of numbers

Create a variable called numbers and set it to an array containing the numbers 1 through 5.

Ruby

# Create the array called numbers
# Your code here

Need a hint?

Use square brackets [] to create an array with the numbers 1 to 5.

2

Set up start time variable

Create a variable called start_time and set it to the current time using Time.now.

Ruby

numbers = [1, 2, 3, 4, 5]
# Set start_time to current time
# Your code here

Need a hint?

Use Time.now to get the current time.

3

Process the numbers with a loop

Use a for loop with the variable num to iterate over numbers. Inside the loop, calculate the square of num and store it in a variable called square.

Ruby

numbers = [1, 2, 3, 4, 5]
start_time = Time.now
# Loop over numbers and calculate square
# Your code here

Need a hint?

Use for num in numbers to loop. Multiply num by itself to get square.

4

Calculate and print elapsed time

Create a variable called end_time and set it to Time.now. Then calculate the elapsed time by subtracting start_time from end_time and store it in elapsed_time. Finally, print the text "Elapsed time: " followed by elapsed_time.

Ruby

numbers = [1, 2, 3, 4, 5]
start_time = Time.now
for num in numbers
  square = num * num
end
# Calculate end_time and elapsed_time, then print elapsed time
# Your code here

Need a hint?

Use Time.now again for end_time. Subtract start_time from end_time. Use puts with string interpolation to print.