exercises

/**
 * ============================================
 * 3.7 SPREAD OPERATOR - EXERCISES
 * ============================================
 */

// ============================================
// EXERCISE 1: Copy an Array
// ============================================
/**
 * Task: Create a copy of the original array using spread operator
 */

const originalArray = [1, 2, 3, 4, 5];
// Your code here:
// const copiedArray = ...

// console.log("Exercise 1:", copiedArray);
// console.log("Are they different?", copiedArray !== originalArray);

// ============================================
// EXERCISE 2: Combine Arrays
// ============================================
/**
 * Task: Combine these three arrays into one using spread
 */

const fruits = ['apple', 'banana'];
const vegetables = ['carrot', 'broccoli'];
const grains = ['rice', 'wheat'];
// Your code here:
// const food = ...

// console.log("Exercise 2:", food);

// ============================================
// EXERCISE 3: Add Elements to Array
// ============================================
/**
 * Task: Create new arrays by adding elements:
 * 1. Add 0 at the beginning of numbers
 * 2. Add 6 at the end of numbers
 * 3. Add 2.5 between 2 and 3
 */

const numbers = [1, 2, 3, 4, 5];
// Your code here:
// const withZero = ...
// const withSix = ...
// const withHalf = ...

// console.log("Exercise 3:");
// console.log("With zero:", withZero);
// console.log("With six:", withSix);
// console.log("With 2.5:", withHalf);

// ============================================
// EXERCISE 4: String to Array and Back
// ============================================
/**
 * Task:
 * 1. Convert the string to an array of characters
 * 2. Reverse the array
 * 3. Join back to string
 */

const word = 'JavaScript';
// Your code here:
// const reversed = ...

// console.log("Exercise 4:", reversed);  // "tpircSavaJ"

// ============================================
// EXERCISE 5: Remove Duplicates
// ============================================
/**
 * Task: Remove duplicates from the array using Set and spread
 */

const withDuplicates = [1, 2, 2, 3, 3, 3, 4, 4, 4, 4];
// Your code here:
// const unique = ...

// console.log("Exercise 5:", unique);  // [1, 2, 3, 4]

// ============================================
// EXERCISE 6: Copy an Object
// ============================================
/**
 * Task: Create a copy of the user object using spread
 */

const originalUser = { name: 'Alice', age: 25 };
// Your code here:
// const userCopy = ...

// console.log("Exercise 6:", userCopy);
// console.log("Are they different?", userCopy !== originalUser);

// ============================================
// EXERCISE 7: Merge Objects
// ============================================
/**
 * Task: Merge defaults with userSettings
 * userSettings should override defaults
 */

const defaults = { theme: 'light', fontSize: 14, showSidebar: true };
const userSettings = { theme: 'dark', fontSize: 18 };
// Your code here:
// const finalSettings = ...

// console.log("Exercise 7:", finalSettings);

// ============================================
// EXERCISE 8: Add Property to Object
// ============================================
/**
 * Task: Create a new object with all product properties plus a 'discount' property
 */

const product = { name: 'Laptop', price: 1000, category: 'Electronics' };
const discountPercent = 10;
// Your code here:
// const productWithDiscount = ...

// console.log("Exercise 8:", productWithDiscount);

// ============================================
// EXERCISE 9: Override Property
// ============================================
/**
 * Task: Create a new config object where debug is set to true
 * while keeping all other properties the same
 */

const config = { debug: false, logLevel: 'error', maxRetries: 3 };
// Your code here:
// const devConfig = ...

// console.log("Exercise 9:", devConfig);

// ============================================
// EXERCISE 10: Conditional Properties
// ============================================
/**
 * Task: Create an order object that includes:
 * - All base order properties
 * - 'express' property only if isExpress is true
 * - 'giftWrap' property only if isGift is true
 */

const baseOrder = { items: ['item1', 'item2'], total: 50 };
const isExpress = true;
const isGift = false;
// Your code here:
// const order = ...

// console.log("Exercise 10:", order);

// ============================================
// EXERCISE 11: Use Spread with Math Functions
// ============================================
/**
 * Task: Find the max, min, and calculate the sum of the scores
 * Use spread operator with Math.max and Math.min
 */

const scores = [85, 92, 78, 96, 88];
// Your code here:
// const maxScore = ...
// const minScore = ...
// const sum = ...(hint: use reduce)

// console.log("Exercise 11:");
// console.log("Max:", maxScore);
// console.log("Min:", minScore);
// console.log("Sum:", sum);

// ============================================
// EXERCISE 12: Call Function with Spread
// ============================================
/**
 * Task: Use spread to pass the date parts to the function
 */

function formatDate(year, month, day) {
  return `${year}-${String(month).padStart(2, '0')}-${String(day).padStart(
    2,
    '0'
  )}`;
}

const dateParts = [2024, 3, 15];
// Your code here:
// const formattedDate = ...

// console.log("Exercise 12:", formattedDate);  // "2024-03-15"

// ============================================
// EXERCISE 13: Immutable Array Update
// ============================================
/**
 * Task: Create a new todos array where the second todo is marked as completed
 * without mutating the original array
 */

const todos = [
  { id: 1, text: 'Learn JS', completed: true },
  { id: 2, text: 'Learn React', completed: false },
  { id: 3, text: 'Build project', completed: false },
];
// Your code here:
// const updatedTodos = ...

// console.log("Exercise 13:");
// console.log("Original:", todos[1].completed);  // false
// console.log("Updated:", updatedTodos[1].completed);  // true

// ============================================
// EXERCISE 14: Remove Property from Object
// ============================================
/**
 * Task: Create a new object without the 'password' property
 * using destructuring and spread
 */

const userWithPassword = {
  id: 1,
  username: 'john_doe',
  email: 'john@example.com',
  password: 'secret123',
};
// Your code here:
// const { ..., ...publicUser } = userWithPassword;

// console.log("Exercise 14:", publicUser);

// ============================================
// BONUS: Deep Merge
// ============================================
/**
 * Task: Create a properly merged settings object where
 * nested objects are also merged (not replaced)
 *
 * Expected result:
 * {
 *   theme: { primary: 'blue', secondary: 'gray', accent: 'yellow' },
 *   layout: { sidebar: true, header: true }
 * }
 */

const baseSettings = {
  theme: { primary: 'blue', secondary: 'gray' },
  layout: { sidebar: true },
};

const overrides = {
  theme: { accent: 'yellow' },
  layout: { header: true },
};

// Your code here:
// const mergedSettings = ...

// console.log("Bonus:", mergedSettings);

// ============================================
// SOLUTIONS
// ============================================
/**
 * Exercise 1:
 * const copiedArray = [...originalArray];
 *
 * Exercise 2:
 * const food = [...fruits, ...vegetables, ...grains];
 *
 * Exercise 3:
 * const withZero = [0, ...numbers];
 * const withSix = [...numbers, 6];
 * const withHalf = [...numbers.slice(0, 2), 2.5, ...numbers.slice(2)];
 *
 * Exercise 4:
 * const reversed = [...word].reverse().join('');
 *
 * Exercise 5:
 * const unique = [...new Set(withDuplicates)];
 *
 * Exercise 6:
 * const userCopy = { ...originalUser };
 *
 * Exercise 7:
 * const finalSettings = { ...defaults, ...userSettings };
 *
 * Exercise 8:
 * const productWithDiscount = { ...product, discount: discountPercent };
 *
 * Exercise 9:
 * const devConfig = { ...config, debug: true };
 *
 * Exercise 10:
 * const order = {
 *     ...baseOrder,
 *     ...(isExpress && { express: true }),
 *     ...(isGift && { giftWrap: true })
 * };
 *
 * Exercise 11:
 * const maxScore = Math.max(...scores);
 * const minScore = Math.min(...scores);
 * const sum = scores.reduce((a, b) => a + b, 0);
 *
 * Exercise 12:
 * const formattedDate = formatDate(...dateParts);
 *
 * Exercise 13:
 * const updatedTodos = todos.map((todo, index) =>
 *     index === 1 ? { ...todo, completed: true } : todo
 * );
 *
 * Exercise 14:
 * const { password, ...publicUser } = userWithPassword;
 *
 * Bonus:
 * const mergedSettings = {
 *     theme: { ...baseSettings.theme, ...overrides.theme },
 *     layout: { ...baseSettings.layout, ...overrides.layout }
 * };
 */