Variables | Year 5 Computing PDF Download

What is a variable?

• The word "vary" means to change or differ.
• Other related words like "variety," "varies," "various," and "variable" are also connected to the concept of change and difference.
• Variables are ubiquitous in our everyday lives because the world is constantly changing!

Variables in everyday life

Let's consider a supermarket checkout scenario:

• When a new shopper arrives at the checkout, the screen initially displays £0.00.
• Each item is scanned through the barcode scanner to determine its price.
• The price of each item varies depending on what it is.
• The scanned price is then added to the total cost displayed on the screen.
• The total cost displayed changes every time a new item is scanned, reflecting the cumulative cost of all items scanned so far.

Understanding Variables in a Computer Program

• Definition of Variables: In the realm of computing, a variable refers to a specific component of a computer program - a series of instructions composed in a coding language that the computer can interpret. This component has the ability to store data that fluctuates or varies as the program executes.
• Analogy of Variables: Think of a variable as a box that holds ever-changing information. The box itself remains constant, but the data it contains can shift.
• Role of Variables: Variables are essential for storing and managing data dynamically within a program. They act as containers for values that can be modified during the program's operation.

More about variables

Variables are fundamental tools in programming. Here's how they operate:

• A program can include multiple variables, each identified by its unique name.
• Each variable can hold and manage one piece of changing information at any given time.
• Variables can store various types of data, such as words, numbers, and values like TRUE or FALSE.
• Once information is stored in a variable, it can be accessed and utilized elsewhere in the program. 

Using Text in a Variable

• A variable in programming can hold both text and numbers, like in our quiz program.
• For instance, we can create a variable named PLAYER NAME to store the name of the player once they input it.

Code Implementation

• The initial code segment directs the game to await a click on the dinosaur before launching the game.
  
• Following that, the code prompts the player with "What's your name?" and waits for a response.
  
• Subsequently, the value entered by the player is assigned to the PLAYER NAME variable.
  
• Lastly, the program displays the content stored in the PLAYER NAME variable after the word "Hello" on the screen, enabling personalized greetings for each player.
  

By utilizing the PLAYER NAME variable in this manner, the quiz can customize greetings for every new player, ensuring a personalized experience as the name changes.

Remembering your details online

• Importance of Cookies: Cookies, small programs, store variable values online, like your name, for account logins and website visits.
• Permission Requests: Websites often ask permission to save these variables for convenience.

Keeping the score

• Utilizing Variables in Programming: Variables assist in decision-making within programs.
• Selection Process: Programs use variables to make decisions, like assessing if a player has won a game based on the score.
• Example: A player wins if their score reaches 10 points.

Winning the game

• Variable Implementation: Variables play a crucial role in programming tools like selection.
• Decision Making: Programs rely on variables to determine the next course of action.
• Game Winning Condition: The program evaluates the player's score to determine if they have won the game, often requiring a specific score threshold for victory.