1. Calculate the Sum of Numbers:

Description: This function calculates the sum of all integers from 1 to 'n'.


function calculateSum(n) {
  let sum = 0;
  for (let i = 1; i <= n; i++) {
    sum += i;
  }
  return sum;
}

Test Case:

console.log("Sum of numbers from 1 to 5:", calculateSum(5)); // Output: 15


2. Factorial Calculation:

Description: This function computes the factorial of a number 'n', which is the product of all positive integers from 1 to 'n'.


function calculateFactorial(n) {
  let factorial = 1;
  for (let i = 1; i <= n; i++) {
    factorial *= i;
  }
  return factorial;
}

Test Case:

console.log("Factorial of 4:", calculateFactorial(4)); // Output: 24


3. Print Multiplication Table:

Description: This function prints the multiplication table for a given number 'n'.


function printMultiplicationTable(n) {
  for (let i = 1; i <= 10; i++) {
    console.log(`${n} x ${i} = ${n * i}`);
  }
}

Test Case:

console.log("Multiplication table for 3:");
printMultiplicationTable(3);


4. Reverse a String:

Description: This function reverses a given string.


function reverseString(str) {
  return str.split('').reverse().join('');
}

Test Case:

console.log("Reversed string:", reverseString("Hello")); // Output: "olleH"


5. Check Even or Odd:

Description: This function checks if a given number is even or odd.


function isEvenOrOdd(num) {
  return num % 2 === 0 ? "Even" : "Odd";
}

Test Case:

console.log("Is 7 even or odd:", isEvenOrOdd(7)); // Output: "Odd"


6. Count Vowels in a String:

Description: This function counts the number of vowels in a given string.


function countVowels(str) {
  return str.match(/[aeiouAEIOU]/g).length;
}

Test Case:

console.log("Number of vowels in 'Hello':", countVowels("Hello")); // Output: 2


7. Find the Maximum Number:

Description: This function finds the maximum number from an array of numbers.


function findMax(arr) {
  return Math.max(...arr);
}

Test Case:

console.log("Maximum number in [5, 10, 3, 8]:", findMax([5, 10, 3, 8])); // Output: 10


8. Calculate the Square of a Number:

Description: This function calculates the square of a given number.


function squareNumber(num) {
  return num * num;
}

Test Case:

console.log("Square of 6:", squareNumber(6)); // Output: 36