Subroutines in algorithm

What is a subroutine in computer programming?

• A type of new computer

• A named block of code that can be called many times

• A coloured button on the keyboard

• A list of folders on your computer

Answer explanation

A subroutine is a named block of code that can be reused multiple times throughout a program, allowing for better organization and efficiency in coding.

Why would you use a subroutine instead of writing the same code many times?

• To make your program longer

• To save time and make changes in only one place

• To confuse other people

• Because subroutines cannot return values

Answer explanation

Using a subroutine allows you to save time by avoiding code duplication. It also makes maintenance easier, as changes can be made in one place rather than multiple locations, reducing errors and improving code clarity.

According to the subroutine guide, how often can you use the same subroutine in a program?

• Only once

• Twice

• As many times as needed

• Only if the teacher says so

Answer explanation

You can use the same subroutine as many times as needed in a program. This allows for code reusability and efficiency, making it easier to manage and maintain your code.

Which statement is not a benefit of using a subroutine?

• It makes the code easier to reuse

• It saves you typing the same lines of code repeatedly

• It helps keep your program organised

• It hides errors so you don’t have to fix them

Answer explanation

The statement 'It hides errors so you don’t have to fix them' is not a benefit of using a subroutine. Subroutines help organize and reuse code, but they do not conceal errors; errors must still be addressed.

How do you call a subroutine that requires inputs?

• By writing its name and putting the input values in parentheses

• By shouting its name

• By saving it to the desktop

• By pressing the Escape key

Answer explanation

A subroutine that requires inputs is called by writing its name followed by the input values in parentheses. This syntax is standard in many programming languages, allowing the subroutine to receive the necessary data to execute.

What is an argument to a subroutine?

• The end of a program

• A value you pass into the subroutine to use in its calculations

• A heated debate with your computer

• Another name for a bug

Answer explanation

An argument to a subroutine is a value you pass into it for calculations. This allows the subroutine to perform operations using that specific data, making it flexible and reusable.

If you have a subroutine that draws a square on the screen and you call it four times, how many squares will be drawn?

• One

• Two

• Three

• Four

Answer explanation

Calling the subroutine that draws a square four times will result in four separate squares being drawn on the screen. Therefore, the correct answer is Four.

What happens if you need to change how a task is done and you have used a subroutine?

• You must change the code in every place you call it

• You only change the code inside the subroutine

• The program stops working

• The change cannot be made

Answer explanation

When using a subroutine, you only need to change the code inside the subroutine itself. This allows for easier maintenance and updates, as changes are centralized rather than scattered across multiple locations in the code.

Which of the following tasks is a good candidate for a subroutine?

• Printing the instructions on the screen at the start of each level

• Typing your name once

• Changing the computer’s language

• Turning off the computer

Answer explanation

Printing the instructions at the start of each level is repetitive and can be reused, making it a good candidate for a subroutine. The other tasks are either one-time actions or not suitable for modularization.

Why might you create a “library” of subroutines?

• To share common tasks across different programs

• To make your computer run slower

• To delete old programs

• Because libraries are only for reading books

Answer explanation

Creating a library of subroutines allows you to share common tasks across different programs, promoting code reuse and efficiency. This is essential for reducing redundancy and improving maintainability in software development.