AP CSP Functions and Parameters Review

Which keyword begins a function **definition** in Python?

• def
• func
• define
• lambda

Answer explanation

`def` starts a function definition.

What are the items inside the parentheses in a function header called?

• Returns
• Parameters
• Arguments
• Keywords

Answer explanation

Parameters are names in the function header; arguments are values at call time.

By default, what does a function **return** if it has no return statement?

• 0
• False
• None
• An empty string

Answer explanation

If no `return` is encountered, Python returns `None`.

Which line correctly **calls** a function named `greet` with one argument `"Ada"`?

• greet{'Ada'}
• greet['Ada']
• greet('Ada')
• def greet('Ada')

Answer explanation

Function calls use parentheses: `name(args)`.

What symbol ends a Python function header line?

• Semicolon (;)
• Colon (:)
• Period (.)
• Comma (,)

Answer explanation

Function headers end with a colon in Python.

Where does a function's **local variable** exist?

• Only inside that function
• Everywhere in the program
• Across different files
• In the Python shell only

Answer explanation

Local variables have scope limited to the function.

What is the correct term for the value you pass into a function when calling it?

• Parameter
• Argument
• Return
• Scope

Answer explanation

Arguments are the values supplied to parameters.

Which of the following is a **valid** function name?

• 2sum
• sum_values
• sum-values
• sum values

Answer explanation

Identifiers cannot start with a digit or include spaces/hyphens.

What does the `return` statement do?

• Prints text on the screen
• Ends the program
• Sends a value back to the caller
• Defines a variable

Answer explanation

`return` hands a value back and exits the function.

What is printed by: ```python def f(): print("X") f() ```

• X
• None
• f
• Error

Answer explanation

Calling `f()` executes its body and prints X.