Increment counter inside an array C#

Question

I want to increment (using a counter) the value of a C# array. However I always get an error:

Index was outside the bounds of the array.

Here is my code.

while ((line = s.ReadLine()) != null)
{

    string[] parts = new string[40];
    parts=line.Split(' ');
    int a;
    for (a = 0; a <= (parts.Length - 1); a++)
    {

        if (parts[a] == "if")
        {
            node = node + 1;
            edge = edge + 1;
            int b = a + 2;
            Console.Write(parts[b]);
            if ((parts[a + 2]) == "{")
            {
                node = node + 1;
            } 
        }
    }
}

On which line? Did you debug your code? ericlippert.com/2014/03/05/how-to-debug-small-programs You can find your problem easily with debugging. — Soner Gönül
– Soner Gönül, Commented Apr 26, 2014 at 12:38
new string[40] is a waste of time and memory because the next statement assigns a new value. Just use var part = line.Split(' '); — Richard Schneider
– Richard Schneider, Commented Apr 26, 2014 at 13:02

Reza · Accepted Answer · 2014-04-26 12:38:46Z

5

The problem is parts[a + 2] when you reached to the end a+2 is out of bounds of array

answered Apr 26, 2014 at 12:38

Reza

20.1k18 gold badges102 silver badges177 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Nazeem · Accepted Answer · 2014-04-26 12:46:13Z

Did you check that

parts[a + 2] doesn't exceed the array length?

One solution could be as follows:

while ((line = s.ReadLine()) != null)
{

    string[] parts = new string[40];
    parts=line.Split(' ');
    int a;
    for (a = 0; a <= (parts.Length - 1); a++)
    {

        if (parts[a] == "if")
        {
            node = node + 1;
            edge = edge + 1;
            int b = a + 2;
            Console.Write(parts[b]);
            if (((a + 2) < parts.length) && (parts[a + 2]) == "{")
            {
                node = node + 1;
            } 
        }
    }
}

In the code an extra check is put to see if a + 2 doesn't exceed the length of the parts-array. Then, the check is done, if the contents at array index a + 2 is equal to "{". If both conditions are true, then the code inside the block is evaluated.

dorien · Accepted Answer · 2014-04-26 12:43:09Z

0

If you use parts[a+2] you can only do the for loop until parts.Lenth -2:

while ((line = s.ReadLine()) != null)
{

    string[] parts = new string[40];
    parts=line.Split(' ');
    int a;
    for (a = 0; a <= (parts.Length - 2); a++)
    {

        if (parts[a] == "if")
        {
            node = node + 1;
            edge = edge + 1;
            int b = a + 2;
            Console.Write(parts[b]);
            if ((parts[a + 2]) == "{")
            {
                node = node + 1;
            } 
        }
    }
}

answered Apr 26, 2014 at 12:43

dorien

5,41711 gold badges67 silver badges123 bronze badges

Comments

Delta · Accepted Answer · 2014-04-26 15:30:35Z

0

Your problem is here

int b = a + 2;
Console.Write(parts[b]); // here is the first problem
if ((parts[a + 2]) == "{") // why do a+2 here when you know parts[b] is the same thing (a +2)
{
      node = node + 1;
}

answered Apr 26, 2014 at 15:30

Delta

8611 gold badge6 silver badges12 bronze badges

Collectives™ on Stack Overflow

Increment counter inside an array C#

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related