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Lesson 5

Lesson 5 of 16

Boolean Operators

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Code Example

raining = true;
warm = false;
console.log(raining && warm); // false

// Do you have a ticket AND is the movie starting?
let hasTicket = true;
let movieStarting = true;
console.log(hasTicket && movieStarting); // true

// Is the game over AND did you get a high score?
let gameOver = true;
let highScore = false;
console.log(gameOver && highScore); // false

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The && symbol is like a checklist where every single box must be checked "Yes."
If you have two things to check and one of them is false, the computer gives up and says "false."
It is perfect for rules, like saying you need to be the right age AND have enough money to buy a toy.
Think of it like a "Both or Nothing" rule—it only says true when both sides match perfectly.

Code Example

cold = true;
snowing = false;
console.log(raining || warm); // true

// Do you have a coupon OR is it a free-cookie day?
let hasCoupon = true;
let freeDay = false;
console.log(hasCoupon || freeDay); // true

// Is it the weekend OR are you on summer break?
let isWeekend = false;
let isSummer = false;
console.log(isWeekend || isSummer); // false

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The || symbol is like a "One or the Other" rule; the computer is happy if just one side is true.
It only says false if both sides are wrong at the same time, like having no weekend and no summer break.
You can use this to let a player win if they find the gold key OR if they find the secret back door.
Think of it like a "Pick Your Way" path—as long as one path is open, you can keep going!

Code Example

cold = true;
snowing = false;
console.log(!cold); // false
console.log(!snowing); //true

// If the game is NOT over, keep playing!
let gameOver = false;
console.log(!gameOver); // true

// If the light is NOT on, it must be dark.
let lightOn = true;
console.log(!lightOn); // false

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The ! symbol is like a "Reverse Button" that flips a value to its exact opposite.
It turns false into true and turns true into false.
You can use it to check if a player is NOT out of health or if a door is NOT locked.
Think of it like playing "Opposite Day"—whatever you tell the computer, it believes the other way!

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Boolean Operators

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Lesson 5 of 16

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raining = true; warm = false; console.log(raining && warm); // false // Do you have a ticket AND is the movie starting? let hasTicket = true; let movieStarting = true; console.log(hasTicket && movieStarting); // true // Is the game over AND did you get a high score? let gameOver = true; let highScore = false; console.log(gameOver && highScore); // false

cold = true; snowing = false; console.log(raining || warm); // true // Do you have a coupon OR is it a free-cookie day? let hasCoupon = true; let freeDay = false; console.log(hasCoupon || freeDay); // true // Is it the weekend OR are you on summer break? let isWeekend = false; let isSummer = false; console.log(isWeekend || isSummer); // false

cold = true; snowing = false; console.log(!cold); // false console.log(!snowing); //true // If the game is NOT over, keep playing! let gameOver = false; console.log(!gameOver); // true // If the light is NOT on, it must be dark. let lightOn = true; console.log(!lightOn); // false