LEARN JAVASCRIPT
🚀 Learning resource for all JavaScript enthusiasts out there! 🌐💡
Coding Exercises and explanations!
10 engaging JavaScript Coding Exercises centered around Control Structures. These exercises are not only a great way to test your JS skills but also to deepen your understanding of core concepts in a practical, hands-on manner. 🛠️🖥️
From basic loops to complex conditional statements, these exercises cover:
- Even or Odd
- Grade Calculator
- Sum of Numbers
- Multiplication Table
- Counting Vowels
- FizzBuzz Challenge
- Reverse a String
Exercise: Even or Odd
Write a JavaScript function that checks whether a number is even or odd.
Solution:
function checkEvenOdd(num) {
return num % 2 === 0 ? “Even” : “Odd”;
}
console.log(checkEvenOdd(4)); // Output: Even
console.log(checkEvenOdd(5)); // Output: Odd
Explanation: The % operator returns the remainder. If a number is divisible by 2 (remainder 0), it’s even; otherwise, it’s odd.
Exercise: Grade Calculator
Implement a function that assigns a letter grade (A, B, C, D, F) based on a score out of 100.
Solution:
function calculateGrade(score) {
if (score >= 90) return ‘A’;
if (score >= 80) return ‘B’;
if (score >= 70) return ‘C’;
if (score >= 60) return ‘D’;
return ‘F’;
}
console.log(calculateGrade(85)); // Output: B
Explanation: This exercise demonstrates the use of multiple if statements to evaluate conditions in sequence.
Exercise: Sum of Numbers
Create a JavaScript function to sum all numbers from 1 to a given number using a for loop.
Solution:
function sumNumbers(n) {
let sum = 0;
for (let i = 1; i <= n; i++) {
sum += i;
}
return sum;
}
console.log(sumNumbers(5)); // Output: 15
Explanation: This uses a for loop to iterate through numbers from 1 to n, accumulating their sum.
Exercise: Multiplication Table
Write a function that generates a multiplication table for a number up to 10.
Solution:
function multiplicationTable(num) {
for (let i = 1; i <= 10; i++) {
console.log(`${num} x ${i} = ${num * i}`);
}
}
multiplicationTable(3);
Explanation: The for loop iterates and calculates the product of the number with the iterator, printing each line of the table.
Exercise: Counting Vowels
Implement a JavaScript function to count the number of vowels in a string.
Solution:
function countVowels(str) {
const vowels = ‘aeiou’;
let count = 0;
for (let char of str.toLowerCase()) {
if (vowels.includes(char)) {
count++;
}
}
return count;
}
console.log(countVowels(‘Hello World’)); // Output: 3
Explanation: This uses a for…of loop to iterate over each character and checks if it’s a vowel.
Exercise: FizzBuzz
Write a function that prints ‘Fizz’ for numbers divisible by 3, ‘Buzz’ for numbers divisible by 5, and ‘FizzBuzz’ for numbers divisible by both 3 and 5, up to a given number.
Solution:
function fizzBuzz(n) {
for (let i = 1; i <= n; i++) {
let output = ”;
if (i % 3 === 0) output += ‘Fizz’;
if (i % 5 === 0) output += ‘Buzz’;
console.log(output || i);
}
}
fizzBuzz(15);
Explanation: The for loop iterates and uses conditional statements to determine what to print.
Exercise: Reverse a String
Implement a function to reverse a string.
Solution:
function reverseString(str) {
let reversed = ”;
for (let i = str.length – 1; i >= 0; i–) {
reversed += str[i];
}
return reversed;
}
console.log(reverseString(‘hello’)); // Output: olleh
Explanation: Loop backwards through the string, appending each character to a new string.