• 3.15 Random Values 🎲
  • 🔥 The Magic Formula
    • Random number from 1 to 6 (like a dice)
  • 🎮 Random Choice from a List
  • 🎯 50/50 Chance (Coin Flip)
  • 🎁 Challenge: Loot Box!

3.15 Random Values 🎲

Random Values = unpredictable numbers (like rolling dice!)

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🔥 The Magic Formula

Random number from 1 to 6 (like a dice)

Math.floor(Math.random() * 6) + 1

How it works:

• Math.random() gives a decimal like 0.4827
• * 6 makes it bigger: 2.8962
• Math.floor() chops off decimals: 2
• + 1 shifts it up: 3 ✅

Want different numbers? Change the 6!

• Math.floor(Math.random() * 10) + 1 → 1 to 10
• Math.floor(Math.random() * 100) + 1 → 1 to 100

%%javascript
// 🎲 Roll a dice! Run this cell multiple times!

const diceRoll = Math.floor(Math.random() * 6) + 1;
console.log(`You rolled: ${diceRoll}`);

---

%%javascript
// 🎯 Try it yourself! Change the numbers

// Random number 1-10
const random10 = Math.floor(Math.random() * 10) + 1;
console.log(`Random 1-10: ${random10}`);

// Random number 1-100
const random100 = Math.floor(Math.random() * 100) + 1;
console.log(`Random 1-100: ${random100}`);

---

🎮 Random Choice from a List

Pick one random item from an array:

const colors = ["red", "blue", "green"];
const randomColor = colors[Math.floor(Math.random() * colors.length)];

The trick: colors.length tells you how many items (3), so you get 0, 1, or 2!

%%js

// 🎨 Pick a random color!

const colors = ["🔴 Red", "🔵 Blue", "🟢 Green", "🟡 Yellow"];
const randomColor = colors[Math.floor(Math.random() * colors.length)];
console.log(`You got: ${randomColor}`);

// Run multiple times to see different colors!

---

🎯 50/50 Chance (Coin Flip)

if (Math.random() < 0.5) {
    console.log("Heads");  // 50% chance
} else {
    console.log("Tails");  // 50% chance
}

Why 0.5? Math.random() gives 0 to 0.999…, so half the time it’s less than 0.5!

%%js

// 🪙 Flip a coin!

if (Math.random() < 0.5) {
    console.log("🪙 Heads!");
} else {
    console.log("🪙 Tails!");
}

// Run it 10 times - you'll get about 5 heads and 5 tails!

---

🎁 Challenge: Loot Box!

Use random to make a simple game where you have different chances:

• 70% chance = Common
• 25% chance = Rare
• 5% chance = Legendary

%%javascript
// 🎁 Open a loot box!

const chance = Math.random();  // Get random number 0 to 0.999...

if (chance < 0.70) {
    console.log("⚪ Common Item");  // 0 to 0.70 = 70%
} else if (chance < 0.95) {
    console.log("🔵 Rare Item");   // 0.70 to 0.95 = 25%
} else {
    console.log("🟡 Legendary!");  // 0.95 to 1 = 5%
}

// Run this many times - legendary is rare!

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