What’s your alternative solution? Challenge #6

#challenges #discuss #javascript #codenewbie

Mar 31, 2020 ・1 min read

About this series

This is series of daily JavaScript coding challenges... for both beginners and advanced users.

Each day I’m gone present you a very simple coding challenge, together with the solution. The solution is intentionally written in a didactic way using classic JavaScript syntax in order to be accessible to coders of all levels.

Solutions are designed with increase level of complexity.

Today’s coding challenge

Calculate 10! (factorial of 10).

(scroll down for solution)

Code newbies

If you are a code newbie, try to work on the solution on your own. After you finish it, or if you need help, please consult the provided solution.

Advanced developers

Please provide alternative solutions in the comments below.

You can solve it using functional concepts or solve it using a different algorithm... or just solve it using the latest ES innovations.

By providing a new solution you can show code newbies different ways to solve the same problem.

Solution

// Solution for challenge06

var prod = 1;

for(var i = 1; i <= 10; i++)
{
    prod *= i;
}

println(prod);

To quickly verify this solution, copy the code above in this coding editor and press "Run".

Note: The solution was originally designed for codeguppy.com environment, and therefore is making use of println. This is the almost equivalent of console.log in other environments. Please feel free to use your preferred coding playground / environment when implementing your solution.

Discussion (6)

Görkem • Mar 31 '20 • Edited

let prod = 1;
[...Array(10).keys()].map(x => {
  ++x;
  prod *= x;
});
console.log(prod);

Lukáš Zahradník • Mar 31 '20 • Edited

This is an example of wrong usage of map.

Bharath Sriraam R R • Mar 31 '20

May I know what you mean by "wrong"? If you mean inefficient please do elaborate, I would like to hear about it!

Lukáš Zahradník • Mar 31 '20 • Edited

Well, it is inefficient as well.

In this example the map is just exploited for iterating over elements and completely ignores purpose of the function (transforming array to a new array). It would be better to use forEach or reduce instead.