Using Parameters and Arguments in JavaScript Functions: AP CSP Examples

📚 Quick Study Guide

• ⚙️ Parameters: Variables listed inside the parentheses of a function definition. They act as placeholders for values that the function will receive.
• 🧮 Arguments: The actual values that are passed to a function when it is called. These values are assigned to the corresponding parameters.
• 📝 Function Definition: ```javascript function myFunction(parameter1, parameter2) { // Function body } ```
• 📞 Function Call: ```javascript myFunction(argument1, argument2); ```
• ➡️ Order Matters: Arguments are passed to parameters in the order they appear. The first argument is assigned to the first parameter, the second argument to the second parameter, and so on.
• 🔑 Scope: Parameters are local to the function. They can only be accessed within the function's body.
• 💡 AP CSP Context: Understanding how to pass information into functions is crucial for creating modular and reusable code, a key concept in AP Computer Science Principles.

Practice Quiz

1. Which of the following best describes a parameter in a JavaScript function?

   1. A) A value passed into a function when it is called.
   2. B) A variable declared within a function's body.
   3. C) A placeholder in a function definition for a value that will be received.
   4. D) The return value of a function.

2. What is the term for the actual value passed to a function when it is called?

   1. A) Parameter
   2. B) Argument
   3. C) Variable
   4. D) Constant

3. Given the function definition `function greet(name)`, what is `name`?

   1. A) An argument
   2. B) A parameter
   3. C) A variable
   4. D) A string

4. If a function is defined as `function add(x, y)`, and it is called as `add(5, 3)`, what are 5 and 3?

   1. A) Parameters
   2. B) Arguments
   3. C) Variables
   4. D) Functions

5. In JavaScript, what happens if you call a function with fewer arguments than parameters?

   1. A) An error is thrown.
   2. B) The missing parameters are assigned a value of `null`.
   3. C) The missing parameters are assigned a value of `undefined`.
   4. D) The function uses default values for the missing parameters.

6. Why are parameters and arguments important in programming?

   1. A) They allow functions to be more specific.
   2. B) They allow functions to be more reusable and flexible.
   3. C) They make code shorter.
   4. D) They are only important for mathematical functions.

7. Consider the following code: `function calculateArea(length, width) { return length * width; }`. What will `calculateArea(4)` return?

   1. A) 4
   2. B) 16
   3. C) `NaN`
   4. D) `undefined`