Question

Look at the following function definition: def do_something(number): return number * 2 a. What is the name of the function? b. What does the function do? c. Given the function definition, what will the following statement display? print(do_something(10))

Short answer

Answer: The name of the function is "do_something". The function doubles its input. The output of the statement "print(do_something(10))" is 20.

Step-by-step solution

Identifying the function's name

The function's name is the first thing that comes after the "def" keyword. In this case, we can see that the name of the function is "do_something".

Understanding the function's purpose

To understand what the function does, we need to look at the code inside the function. Here, we see a single line of code: "return number * 2". This means that the function takes an input (called "number") and returns the result after multiplying the input by 2. The function essentially doubles its input.

Evaluating the given statement

We're given a statement to evaluate: "print(do_something(10))". We need to substitute the number 10 into the function "do_something" and compute the result. Since we know that the function doubles its input, the result will be 10 * 2 which equals 20. So, the output displayed by the statement will be 20.

Key concepts

Function Name

When learning about Python functions, the function name is the identifier you use to call and execute a specific block of code. In Python, functions are defined using the `def` keyword, followed by the function name. The function name is crucial because it allows us to refer back to the function whenever we need its functionality. For example, consider the function:

• def do_something(number):

In this case, the function name is do_something. It's important to choose descriptive names that hint at what the function does, which makes your code easier to read and maintain.

Function Purpose

The purpose of a function is to perform a specific task or computation. Understanding the function's purpose requires examining the code within the function body. In the defined function `do_something(number):`, the purpose is clear from the line:

• return number * 2

This line indicates that the function takes an input called `number`, multiplies it by 2, and returns the resulting value. In this case, the function's purpose is to double its input. Functions encapsulate specific computations to keep code organized, reusable, and streamlined.

Return Statement

A critical feature of Python functions is the return statement. The return statement determines what a function gives back after it finishes executing. In the given function `do_something(number):`, the return statement is:

• return number * 2

This statement instructs the function to output the result of `number * 2`. Without a return statement, a function would not provide a usable result back to the caller. Thus, return statements are essential in controlling what is handed back when a function completes execution. It signals the end of the function's execution, often carrying along a value that is then used elsewhere in the program.

Function Call

A function call is the execution trigger for a function. It involves using the function's name followed by parentheses, which can contain arguments. In our example, the function call is structured as:

• print(do_something(10))

Here, `do_something(10)` is the function call, which computes the value 10 doubled, resulting in 20. The `print` statement is used to display this result. Function calls are crucial because they activate the logic contained within the function, making it possible to perform operations, calculations, or actions defined in the function body from different parts of your code.