Visual Studio 环境变量 OUTPUT_PATH

Question

I'm getting this error trying to solve simple problem using Visual Studio 2019

System.ArgumentNullException: 'Value cannot be null. Parameter name: path'

This is the line of code causing the error:

TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

Is it something wrong with my environment variable? If that so, how can I fix this?

Full code below:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Solution
{
    /*
     * Complete the simpleArraySum function below.
     */
    static int simpleArraySum(int[] ar)
    {
        /*
         * Write your code here.
         */
        return 0;
    }

    static void Main(string[] args)
    {
        TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

        int arCount = Convert.ToInt32(Console.ReadLine());

        int[] ar = Array.ConvertAll(Console.ReadLine().Split(' '), arTemp => Convert.ToInt32(arTemp));
        int result = simpleArraySum(ar);

        textWriter.WriteLine(result);

        textWriter.Flush();
        textWriter.Close();
    }
}

Answer 1

You shouldn't use the environment variable "OUTPUT_PATH". It's not a standard variable on every machine.

Try write to a folder relative to the exe or some other folders such documents in "%userprofile%"