What is a Variable?

Learning Objectives Differentiate between number, string, and boolean data types. Trace and predict the changing value of a variable inside a loop. Implement a counter variable to control how many times a loop runs. Use a boolean variable (a 'flag') to make decisions in a conditional statement. Explain why clear and consistent variable naming is important for writing readable code. Define 'variable scope' with a simple analogy and identify where a variable can be used in a block of code. Ever wonder how a game remembers your high score or the color of your character's hair, even after you've played for hours? 🎮 It's all thanks to the power of variables! You've used variables before, but now we're going to unlock their secret pow...

TermDefinitionExample Data TypeThe type of information a variable holds. Just like you have different boxes for toys and for snacks, variables have different types for different data.A variable `playerScore` holds a Number (like 150), `playerName` holds a String (like 'Alex'), and `isGameOver` holds a Boolean (like `true` or `false`). InitializationThe very first time you create a variable and give it a value.`let score = 0;` This initializes a variable named `score` with a starting value of 0. ReassignmentChanging the value of a variable that already exists.If we have `score = 10;`, we can reassign it later with `score = 20;`. The old value of 10 is replaced. Counter VariableA variable, usually a number, that is used to count events or the number of times a loop has run.In a lo...

The Counter Pattern variable = variable + 1 This is the most common way to make a counter variable go up by one. You take the variable's current value, add one to it, and then save that new value back into the same variable. It's essential for counting in loops. The Boolean Check if (booleanVariable == true) { ... } Use this pattern to make decisions. The code inside the `{}` will only run if the boolean variable's value is `true`. This is how you check if a player has a key, if the game is over, or if a setting is turned on. Variable Naming Convention (camelCase) startWithLowerCaseAndCapitalizeEachNewWord When naming variables, make them easy to read. A common rule is 'camelCase', where the first word is lowercase and every new word after it...