indexOutOfRangeExeption was unhadled error

Henry Lhteenmaki

Hi !

I have made this program , and for some reason I got a error in line 33 that says :indexOutOfRangeExeption was unhadled.

could you please, explain to me what mistake I have done in the program .

Br

Henry

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

namespace Assignment3
{
    class Program
    {
        static void Main(string[] args)
        {
            string name, message = " ";
            int average = 0 ;

            //Users names

            Console.WriteLine("Enter you name");
            name = Console.ReadLine();

            // Declare variables the type array

            string[] var = { "first", "second", "third" };
            int[] scores = new int[3];


            // loop trought the arrays

            for (int i = 1 ; i <= var.Length; i ++) {

                 try
                {
                    Console.WriteLine("Enter your {0}, score", var[i]);
                    scores[i] = int.Parse(Console.ReadLine());
                    average += scores[i]/3;
                }

                catch (FormatException) {

                    Console.WriteLine("the {0}, is Not a numeric value ", scores[i]);


                }
            }


            // Testing the average

            if (average >= 90 && average <= 100)
            {

                message = "Wow, you did great";
            }

            else if (average >= 80 && average <= 89)
            {

                 message = "Pretty good!";
            }

            else if (average >= 75 && average <= 79)
            {

                message = "That was close....";

            }

            else if (average < 75)
            {

                message = "Better luck next time";

            }



            Console.WriteLine("Hi {0}, {1}", name, message);
            Console.ReadLine();
            return;
            }
        }
    }

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
while(true) is one of the ways in which you can create an infinite loop in C#.

The idea is that, if there's an exception, there will be another iteration of the loop.

However, if the code manages to reach the 'break' statement, then you know the input was OK and so you can safely exit the loop.
Henry Lhteenmaki14y ago
Great ! good way

thanks a lot

would like please to explain to me what while (true) means in this case ?

again thanks
Vulpes14y ago
You could do it like this and also check that the score is within limits (between 0 and 100) at the same time:

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

namespace Assignment3
{
class Program
{
static void Main(string[] args)
{
string name, message = " ";
int average = 0 ;

//Users names

Console.WriteLine("Enter you name");
name = Console.ReadLine();

// Declare variables the type array

string[] var = { "first", "second", "third" };
int[] scores = new int[3];


// loop trought the arrays

for (int i = 0 ; i < var.Length; i++) {

while(true)
{
string input = null;

try
{
Console.WriteLine("Enter your {0}, score", var[i]);
input = Console.ReadLine();
scores[i] = int.Parse(input);
if (scores[i] < 0 || scores[i] > 100)
{
Console.WriteLine("{0}, is Not a valid score ", input);
continue;
}
average += scores[i];
break;
}

catch (FormatException) {

Console.WriteLine("{0}, is Not a numeric value ", input);
}
}
}

average = average/3;

// Testing the average

if (average >= 90 && average <= 100)
{

message = "Wow, you did great";
}

else if (average >= 80 && average <= 89)
{

message = "Pretty good!";
}

else if (average >= 75 && average <= 79)
{

message = "That was close....";

}

else if (average < 75)
{

message = "Better luck next time";

}



Console.WriteLine("Hi {0}, {1}", name, message);
Console.ReadLine();
return;
}
}
}
Henry Lhteenmaki14y ago
When I execute the code even I enter a string by purpose to check if the error handler work properly , the program still continue and ask me to enter the second score , how I can force the program to stop executing other

instruction until the first one will correct (e.g first score )

Br

Henry
Vulpes14y ago
The problem is that array indexing always starts at 0, whereas your 'for' statement is running from 1 to 3. As the last index of the array is 2, you're getting an IndexOutOfRange exception when you try to access an element at index 3.

To remedy this, just change the for statement as I've highlighted below:

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

namespace Assignment3
{
class Program
{
static void Main(string[] args)
{
string name, message = " ";
int average = 0 ;

//Users names

Console.WriteLine("Enter you name");
name = Console.ReadLine();

// Declare variables the type array

string[] var = { "first", "second", "third" };
int[] scores = new int[3];


// loop trought the arrays

for (int i = 0 ; i < var.Length; i++) {

try
{
Console.WriteLine("Enter your {0}, score", var[i]);
scores[i] = int.Parse(Console.ReadLine());
average += scores[i]/3;
}

catch (FormatException) {

Console.WriteLine("the {0}, is Not a numeric value ", scores[i]);


}
}

// Testing the average

if (average >= 90 && average <= 100)
{

message = "Wow, you did great";
}

else if (average >= 80 && average <= 89)
{

message = "Pretty good!";
}

else if (average >= 75 && average <= 79)
{

message = "That was close....";

}

else if (average < 75)
{

message = "Better luck next time";

}



Console.WriteLine("Hi {0}, {1}", name, message);
Console.ReadLine();
return;
}
}
}