Python Function Examples: Learn by Doing (Grade 8 CS)

📚 Quick Study Guide

• ⚙️ A function is a block of organized, reusable code that performs a specific task.
• 🧩 Functions help break down a large program into smaller, manageable parts.
• ➡️ To define a function, use the `def` keyword, followed by the function name and parentheses `()`.
• 🧮 You can pass data into a function using parameters, which are placed inside the parentheses.
• ↩️ Functions can return a value using the `return` statement. If no `return` statement is present, the function returns `None`.
• 📞 To use a function, you need to call it by its name, followed by parentheses `()`.
• 💡 Functions can significantly reduce code duplication and improve readability.

🧪 Practice Quiz

1. Which keyword is used to define a function in Python?
   1. `function`
   2. `define`
   3. `def`
   4. `fun`
2. What happens if a function does not have a `return` statement?
   1. It raises an error.
   2. It returns 0.
   3. It returns `None`.
   4. It returns a random value.
3. What are the values passed into a function called?
   1. Arguments
   2. Parameters
   3. Variables
   4. Inputs
4. How do you call or execute a function in Python?
   1. Using the `execute` keyword.
   2. By typing its name followed by parentheses.
   3. Using the `run` command.
   4. By clicking on it.
5. What is the main benefit of using functions?
   1. It makes the code run faster.
   2. It reduces code duplication and improves readability.
   3. It makes the code more complex.
   4. It is required by Python.
6. Which of the following is a correctly defined function?
   1. `def my_function:`
   2. `function my_function():`
   3. `def my_function():`
   4. `my_function(): def`
7. What does the following function return? ```python def add_numbers(a, b): return a + b result = add_numbers(5, 3)```
   1. 5
   2. 3
   3. 8
   4. None