Getting User Input and Adding it to an array at C#

Question

I am trying to get input from user 5 times and add those values to marks array;

Then, it will calculate the average and print positive or negative accordingly. However, I can not take input from the user it just prints "Enter 5 elements". After getting input from user how can I add them to marks array? Any tips would be helpful.

using System;

    using System.Collections.Generic;
    using System.Linq;
    using System.Text.RegularExpressions;
    class Program
    {
        static void Main()
        {
                double average =0;
                int [] marks = new int[] { };

                 for (int a = 0; a < 5; a++){
                    Console.WriteLine("Enter 5 elements:"); 
                string line = Console.ReadLine(); 
                 Console.WriteLine(line);

            }
                for (int i = 0; i < marks.Length; i++){
                    average = marks.Average();
            }
                if(average>0){
                    Console.WriteLine("Positive");
                }else{
                    Console.WriteLine("Negative");
                }           
        }
    }

You should do something with "line" after reading it. [`int.TryParse(...)`](https://msdn.microsoft.com/en-us/library/f02979c7(v=vs.110).aspx) ought to help you. Also note that you're currently initializing a zero-lenghth array, so you might want to change it to `int[] marks = new int[5];` — ProgrammingLlama, May 04 '18 at 07:40
Depending on how you input the values from the console, it will also make it easier if you input the values comma-delimited. then you can go string[] values = InputStr.split(','); - which is then all string values and do what John said. (Or space- delimited... however you prefer) — Paul, May 04 '18 at 07:46

Slaven Tojić · Accepted Answer · 2018-05-04T08:56:50.813

I would use a while loop combined with int.TryParse to check if the user input is a number. Also it doesn't make any sense to put average = marks.Average(); inside a for loop, because LINQ Average calculates the average of a collection (in your case the marks array).

static void Main()
{
    int[] marks = new int[5];

    int a = 0;

    Console.WriteLine("Enter 5 elements:");

    while (a < 5)
    {
        if (int.TryParse(Console.ReadLine(), out marks[a]))
            a++;
        else
            Console.WriteLine("You didn't enter a number! Please enter again!");
    }

    double average = marks.Average();

    if (average > 0)
        Console.WriteLine("Positive");
    else
        Console.WriteLine("Negative");
}

DEMO HERE

MEC · Answer 2 · 2018-05-04T09:30:14.747

1

Edited my answer to illustrate solving your problem without a for loop.

class Program
{
    const int numberOfMarks = 5;
    static void Main()
    {
        List<int> marks = new List<int>();
        Enumerable.Range(1, numberOfMarks)
        .ForEach((i) => {
            Console.Write($"Enter element {i}:");
            marks.Add(int.TryParse(Console.ReadLine(), out var valueRead) ? valueRead : 0);
            Console.WriteLine($" {valueRead}");
        });
        Console.WriteLine(marks.Average() >= 0 ? "Positive" : "Negative");
    }
}

edited May 04 '18 at 09:30

answered May 04 '18 at 07:49

MEC

1,690
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forgot to mention, it needs MoreLinq for the ForEach. :) – MEC May 04 '18 at 13:15

Shikha Garg · Answer 3 · 2018-05-04T08:45:59.057

0

Follow Stackoverflow Answer

since integer array is being used, and as input from the console is a string value, you need to convert it using Parse() Method. For e.g.

string words = "83";

int number = int.Parse(words);

Edit: using string variable in parsing.

edited May 04 '18 at 08:45

answered May 04 '18 at 07:48

Shikha Garg

1
1

koviroli · Answer 4 · 2018-05-04T08:35:40.710

0

This will help you, just copy and paste it. There are some explanation with comments.

class Program
{
    static void Main()
    {
        const int numberOfMarks = 5;
        int[] marks = new int[numberOfMarks];

        Console.WriteLine("Enter 5 elements:");
        for (int a = 0; a < numberOfMarks; a++)
        {
            // If entered character not a number, give a chance to try again till number not entered
            while(!int.TryParse(Console.ReadLine(), out marks[a]))
            {
                Console.WriteLine("Entered not a character");
            }

            Console.WriteLine("You entered : " + marks[a]);
        }

        // Have to call Average only once.
        var avg = marks.Average();
        Console.WriteLine(avg > 0 ? "Positive average" : "Negative average");
        Console.ReadLine();
    }
}

edited May 04 '18 at 08:35

answered May 04 '18 at 08:07

koviroli

1,422
1
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1

A little tip : you don't need the `intTemp` just use `out marks[a]` in the TryParse. And you can use it after in the `Console.WriteLine` method – Slaven Tojić May 04 '18 at 08:33
That's good point, you are right. Edited my Answer. And realized, almost the same as your code here. – koviroli May 04 '18 at 08:37
It's a simple problem so there are not many solutions to this. – Slaven Tojić May 04 '18 at 08:40
I will upvote you because beside of me you only have a decent answer here – Slaven Tojić May 04 '18 at 08:54

Getting User Input and Adding it to an array at C#

4 Answers4