JavaScript: Calculate the factorial of a number

JavaScript Function: Exercise-1 with Solution

Factorial Calculation

Write a JavaScript program to calculate the factorial of a number.

In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example, 5! = 5 x 4 x 3 x 2 x 1 = 120

Visual Presentation:

Sample Solution-1:

JavaScript Code:

// Recursive JavaScript function to calculate the factorial of a number.

function factorial(x) {
  // Base case: factorial of 0 is 1.
  if (x === 0) {
    return 1;
  }

  // Recursive case: x! = x * (x-1)!
  return x * factorial(x - 1);
}

// Example usage: Calculate and print the factorial of 5.
console.log(factorial(5));

Output:

120

Flowchart:

Live Demo:

See the Pen javascript-recursion-function-exercise-1 by w3resource (@w3resource) on CodePen.

Sample Solution-2:

JavaScript Code:

// Recursive JavaScript function to calculate the factorial of a number.
function factorial(x, result = 1) {
  // Base case: factorial of 0 or 1 is 1.
  if (x === 0 || x === 1) {
    return result;
  }

  // Recursive case: x! = x * (x-1)!
  return factorial(x - 1, x * result);
}
// Example usage: Calculate and print the factorial of 5.
console.log(factorial(5));

Output:

120

Flowchart:

For more Practice: Solve these Related Problems:

• Write a JavaScript function that calculates the factorial of a number using tail recursion for optimization.
• Write a JavaScript function that computes the factorial iteratively without using recursion.
• Write a JavaScript function that calculates the factorial of a number and implements memoization to cache intermediate results.
• Write a JavaScript function that computes the factorial and throws a custom error for negative inputs.

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