JavaScript: Calculate the factorial of a number

Last update on May 30 2022 10:08:47 (UTC/GMT +8 hours)

JavaScript Function: Exercise-1 with Solution

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

Pictorial Presentation:

JavaScript: Calculate the factorial of a number

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Calculate the factorial of a number.</title>
</head>
<body>
</body>
</html>

JavaScript Code:

function factorial(x) 
{ 

  if (x === 0)
 {
    return 1;
 }
  return x * factorial(x-1);
         
}
console.log(factorial(5));

Output:

Flowchart:

Live Demo:

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

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Previous: Javascript Recursion Functions Exercises
Next: Write a JavaScript program to find the greatest common divisor (gcd) of two positive numbers.

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04