How to input in an integer array

Question

How can I take input in an array in C#?

I have written a code it's not working right. For example, if I input 1, then it gives an output 49.

using System;
using System.Collections.Generic;
using System. Linq;
using System.Text;
using System.Threading.Tasks;

namespace Google
{
    class Program
    {
        static void Main(string[] args)
        {
            int n;
            int[] array=new int[26];
            Console.Write("Enter number of cases : ");
            n = Console.Read();
            for (int i = 0; i < n; i++)
            {
                array[i] = Console.Read();
                Console.WriteLine( array[i]);
            }
            Console.Read();
        }  
    }
}

Let me see if I'm understanding your question properly, you're trying to store input from the command prompt into an array? — Ken
– Ken, Commented Jul 22, 2014 at 19:51
+1 for being a rookie and asking a nice question. Next thing start learning about Debugging an application. — Habib
– Habib, Commented Jul 22, 2014 at 19:52
I'm not saying don't help the guy, but this type of question is generally flagged. I guess SO gets sentimental sometimes. — Jonesopolis
– Jonesopolis, Commented Jul 22, 2014 at 19:57
Possible duplicate of stackoverflow.com/questions/26622240/… — Pie
– Pie, Commented Jun 14, 2019 at 19:09

double-beep · Accepted Answer · 2019-06-14 18:59:27Z

6

arr = Array.ConvertAll(Console.ReadLine().Trim().Split(' '),Convert.ToInt32);

edited Jun 14, 2019 at 18:59

double-beep

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answered Jun 14, 2019 at 18:58

Sayak Sinha

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2 Comments

grooveplex Over a year ago

Hi, welcome to Stack Overflow. Please edit your answer to explain the code. Thanks!

KushalSeth Over a year ago

He is basically, trying to split the string input Console.ReadLine().Trim().Split(' '), which is in this form: "7 4". This will output the string array. But he wanted int array, so he has used Array.ConvertAll() to convert to Int32. Array.ConvertAll() method will convert array of one type to array of another type.

pascalh · Accepted Answer · 2014-07-22 19:51:46Z

3

Console.Read returns the character code, not the number you entered.

Use int.Parse(Console.ReadLine()) instead:

n = int.Parse(Console.ReadLine());
//...
array[i] = int.Parse(Console.ReadLine());

answered Jul 22, 2014 at 19:51

pascalh

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Comments

David · Accepted Answer · 2014-07-22 19:55:25Z

3

49 is correct. this number is coming for the ascii value of the character "1" Source (http://www.asciitable.com/)

You need to include a parser for your int.

As Selman22 said:

array[i] = int.Parse(Console.ReadLine());

will work for you.

answered Jul 22, 2014 at 19:55

David

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Comments

Ravibhushan Kumar · Accepted Answer · 2017-04-05 14:03:34Z

Most of the competitive programming take inline integer input as the input array. In that case console input can do this way:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;

namespace CSharp
{
    class Program
    {
        static void Main(string[] args)
        {

            int n;
            n =Int32.Parse(Console.ReadLine());
            int[] arr = new int[n];
            string[] s = Console.ReadLine().Split(' ');

            for (int i= 0;i< n;i++)
            {
                arr[i] = Int32.Parse(s[i]);
            }
            Console.WriteLine(n);
            foreach (var item in arr)
            {
                Console.Write(item+" ");
            }
        }
    }
}

Selman Genç · Accepted Answer · 2014-07-22 20:00:11Z

2

Console.Read method gets the next character from input stream, and converts it to integer value which is the ASCII value of the char. You want Console.ReadLine instead:

array[i] = int.Parse(Console.ReadLine());

Use int.TryParse if you want to validate user's input.

Btw it can be done with Read method if you want to get just numbers from 0 to 9 (which probably you don't), but the code will look ugly:

 array[i] = int.Parse(((char)Console.Read()).ToString());

edited Jul 22, 2014 at 20:00

answered Jul 22, 2014 at 19:51

Selman Genç

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2 Comments

Jeppe Stig Nielsen Over a year ago

Another ugly approach: (int)char.GetNumericValue((char)Console.Read())

Jeppe Stig Nielsen Over a year ago

A hacky approach: Console.Read() - '0'

A-Sharabiani · Accepted Answer · 2019-09-23 18:18:14Z

2

One liner solution:

var array = Console.ReadLine().Split().Select(int.Parse).ToArray();

Explanation

the array will be an array of integers read from the console input in one line separated by space.

Example Input: "1 2 3 4 5".

answered Sep 23, 2019 at 18:18

A-Sharabiani

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Comments

LazyOfT · Accepted Answer · 2014-07-22 19:52:53Z

1

You are reading a char, not a number, in your case it is returning the ASCII value of 1, which is 49. You should use proper parsing functions like Int32.Parse(Console.ReadLine()).

answered Jul 22, 2014 at 19:52

LazyOfT

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Comments

Tim · Accepted Answer · 2014-07-22 19:54:31Z

1

1 coming across as 49 should be your hint. 49 is the ASCII value for the character '1'.

So what's happening is that your Console.Read() call is returning a char which is being implicitly cast as an integer into your integer array.

You probably actually expect the user to type a number and hit enter. So you'd probably be better off using Console.ReadLine() and then using int.TryParse on the string you get from that.

answered Jul 22, 2014 at 19:54

Tim

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