Exercise 1: Reverse a String
Write a function reverseString that takes a string as input and returns the reverse of that string.
function reverseString(str) {
return str.split(”).reverse().join(”);
}
// Example usage:
console.log(reverseString(‘Hello’)); // Output: “olleH”
Exercise 2: Check for Palindrome
Write a function isPalindrome that checks if a given string is a palindrome (reads the same forwards and backwards).
function isPalindrome(str) {
const reversedStr = str.split(”).reverse().join(”);
return str === reversedStr;
}
// Example usage:
console.log(isPalindrome(‘racecar’)); // Output: true
Exercise 3: Find the Maximum Number
Write a function findMax that takes an array of numbers as input and returns the maximum number in the array.
function findMax(numbers) {
return Math.max(…numbers);
}
// Example usage:
console.log(findMax([3, 7, 1, 9, 4])); // Output: 9
Exercise 4: FizzBuzz
Write a function fizzBuzz that prints numbers from 1 to n, but for multiples of 3, print “Fizz” instead, and for multiples of 5, print “Buzz” instead. For numbers that are multiples of both 3 and 5, print “FizzBuzz.”
function fizzBuzz(n) {
for (let i = 1; i <= n; i++) {
if (i % 3 === 0 && i % 5 === 0) {
console.log(‘FizzBuzz’);
} else if (i % 3 === 0) {
console.log(‘Fizz’);
} else if (i % 5 === 0) {
console.log(‘Buzz’);
} else {
console.log(i);
}
}
}
// Example usage:
fizzBuzz(15);
Exercise 5: Calculate Factorial
Write a function factorial that calculates the factorial of a given number.
function factorial(n) {
if (n === 0 || n === 1) {
return 1;
} else {
return n * factorial(n – 1);
}
}
// Example usage:
console.log(factorial(5)); // Output: 120
Exercise 6: Check for Prime Number
Write a function isPrime that checks if a given number is prime (only divisible by 1 and itself).
function isPrime(num) {
if (num <= 1) {
return false;
}
for (let i = 2; i <= Math.sqrt(num); i++) {
if (num % i === 0) {
return false;
}
}
return true;
}
// Example usage:
console.log(isPrime(11)); // Output: true
Exercise 7: Find Fibonacci Sequence
Write a function generateFibonacci that generates the Fibonacci sequence up to a specified number of terms.
function generateFibonacci(n) {
const fibArray = [0, 1];
while (fibArray.length < n) {
const nextValue = fibArray[fibArray.length – 1] + fibArray[fibArray.length – 2];
fibArray.push(nextValue);
}
return fibArray;
}
// Example usage:
console.log(generateFibonacci(10)); // Output: [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
Exercise 8: Find Longest Word
Write a function findLongestWord that takes a string of words and returns the longest word in the string.
function findLongestWord(str) {
const words = str.split(‘ ‘);
let longestWord = ”;
for (const word of words) {
if (word.length > longestWord.length) {
longestWord = word;
}
}
return longestWord;
}
// Example usage:
console.log(findLongestWord(‘This is a sample sentence’)); // Output: “sentence”
Exercise 9: Count Characters
Write a function countCharacters that counts the occurrences of each character in a string and returns the results as an object.
function countCharacters(str) {
const charCount = {};
for (const char of str) {
if (charCount[char]) {
charCount[char]++;
} else {
charCount[char] = 1;
}
}
return charCount;
}
// Example usage:
console.log(countCharacters(‘hello’)); // Output: {h: 1, e: 1, l: 2, o: 1}
Exercise 10: Title Case a Sentence
Write a function titleCase that converts a sentence to title case (the first letter of each word capitalized).
function titleCase(sentence) {
const words = sentence.split(‘ ‘);
const titleCasedWords = words.map(word => word.charAt(0).toUpperCase() + word.slice(1).toLowerCase());
return titleCasedWords.join(‘ ‘);
}
// Example usage:
console.log(titleCase(‘this is a sample sentence’)); // Output: “This Is A Sample Sentence”
These exercises cover a range of JavaScript concepts and are designed to help you practice your coding skills and problem-solving abilities.