Factorial in D

Welcome to the Factorial in D page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

// Factorial program in D
import std.stdio: writeln;
import std.conv: to, ConvException;
import core.stdc.stdlib: exit;

void usage()
{
    writeln("Usage: please input a non-negative integer");
    exit(0);
}

int fac(int a)
{
    if (a <= 1)
    {
        return 1;
    }
    return a*fac(a-1);
}

int main(string[] args)
{
    if (args.length < 2)
    {
        usage();
    }

    int depth;
    try {
        depth = to!int(args[1]);
        if (depth < 0)
        {
            usage();
        }
    }
    catch(ConvException _)
    {
        usage();
    }

    int result = fac(depth);
    writeln(result);
    return 0;
}

Factorial in D was written by:

• rzuckerm
• Scott Little

If you see anything you'd like to change or update, please consider contributing.

Note: The solution shown above is the current solution in the Sample Programs repository as of May 13 2023 20:47:23. The solution was first committed on Oct 04 2020 13:56:29. As a result, documentation below may be outdated.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.