C＃控制台用户输入

Question

Ok, I want to first start off by saying I'm not a student so this question has nothing to do with homework at all. I'm trying to learn C# because the company that I want to work for uses it. I heard that C# is very similar to java so I'm using my java book that has exercise problems to practice c#. Here is my question, I'm trying to make a simple program that the user enters 3 grades and it stores it in an array and then displays the three grades that were entered. The problem is that its not storing the grades. It does however display some random number like if I put in 34, 44, and 54 it returns 51. Here is my code and thanks everyone:

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

namespace Practice1
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] test = new int[4];

            int i = 1;

            for (i = 1; i <= 3; i++)
            {
                Console.WriteLine("Please enter test " + i);
                test[i] = Console.Read();
                Console.ReadLine();

            }
            for (i = 1; i <=3; i++)
            {
                Console.WriteLine(test[i]);
                Console.ReadLine();
            }
        }
    }
}

Answer 1

Your problem is here:

test[i] = Console.Read();

This is putting a character (which is an integer character code) into your test array.

Instead do

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

Edit: If you aren't certain that the user will type a parsable integer, maybe they'll type in "six", for example you might consider using a try/catch (if you want to know why it wouldn't parse), or the int.TryParse, which returns true to indicate success and assigns the parsed integer to a variable, field, or array index:

if(int.TryParse(Console.ReadLine(), out test[1])
   Console.WriteLine("Successfully parsed integer");
else
   Console.WriteLine("Please enter an integer.");

Answer 2

Console.Read() returns the ASCII value of the key entered. For example if you type in "A", you get the value 65 which is the ASCII code for "A".

You will need to parse your string to an integer:

for (i = 0; i < 4; i++)
{
    Console.WriteLine("Please enter test " + i);
    string input = Console.ReadLine();
    int value;
    bool success = int.TryParse(input, out value);
    if (success)
    {
        test[i] = value
    }
    else
    {
        // Show an error message that the user must enter an integer.
    }

    Console.ReadLine();

}                

Also note that arrays are indexed starting with 0 in C#, not with 1 as your code assumes.

Alternatively you can still use Console.Read (), which returns the integer representation of the character entered, confirm that the character is in fact a number, and convert from the ASCII code to the appropriate number.

Answer 3

From the docs Console.Read() "Reads the next character from the standard input stream."

You want the next Integer, so something like

bool cont = false;
int val = 0;
do
{
    cont = int.TryParse(Console.ReadLine(), out val);
    if(!cont){Console.WriteLine( "please enter a real number you fool" );}
} while (!cont);

Should work.

Answer 4

        int[] test = new int[3];

        for (int i = 0; i < 3; i++)
        {
            Console.WriteLine("Please enter test " + i + 1);
            test[i] = Int.Parse(Console.ReadLine());
        }
        for (int i = 0; i < 3; i++)
        {
            Console.WriteLine(test[i]);
            Console.ReadLine();
        }

As you can see, arrays starts from index 0, so there is no need to define int[4] (one more int than required), and you need to loop from index 0 to length-1

Answer 5

The problem is that you are reading in the character. As such the "51" you are seeing is the decimal (base 10) ASCII value for the number 3. What you need to do is the following:

string result = Console.ReadLine();
int grade = 0;
int.TryParse(result, out grade)
test[i] = grade;

Answer 6

Console.Read() returns a character. You want to read a string from the console, convert it to an int , and then store that value in your array.

Answer 7

Here is the code:

int[] test = new int[3];

        for (int e = 0; e < 3; e++)
        {
            Console.WriteLine("Please enter test ");
            test[e] = int.Parse(Console.ReadLine());
        }


        Console.WriteLine("000000000000000000000000000\n");

        for (int e = 0; e < 3; e++)
        {

            Console.WriteLine(test[e]);
            //Console.ReadLine();

        }