C# - Generate Array at runtime

Mastermosley

I have an array char[] buffer but I dont want to initialize it because I dont no how big its going to be. I have a simple StreamReader.Read() and I am processing each character, if the character is legit I add it to the buffer.

buffer[buffersize] = c;
buffersize++;

And if the char is a \r or \n thats a new line so I send the final buffer and process the command

if the char is 8 which is a backspace I want to delete the last character in the array.

buffersize--;

What I want to accomplish is that by subtracting 1 from the buffersize I want to delete the buffer[buffersize].

Any ideas am I missing something?

5 Replies

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theLizard15y ago
Dynamic array, only add an element when you need to.

            char[] buffer = new char[0];

            char c = '\n';

            if (c != '\b') //only add the char if it is NOT the backspace, you can also test for other char values
                {
                Array.Resize(ref buffer, buffer.Length + 1);
                buffer[buffer.Length - 1] = c;
                }

        To remove last element in array as you have indicated with buffersize--   do this with Array,Resize(ref buffer, buffer.length -1); but if you don;t put it in the array in the first place you wont need to remove it.
Sam Hobbs15y ago
Also look at the StringBuilder Class.
Vulpes15y ago
When you're dealing with chars it's better to use a List rather than an ArrayList. This is because the latter stores everything internally as an object and so value types such as char need to be 'boxed' on the heap and then, when they're retrieved, 'unboxed' (by casting to char) which is a relatively slow process.

In contrast the elements of a List are stored internally as chars and so no boxing or casting is required.

List buffer = new List();

using (StreamReader sr = new StreamReader(path))
{
while (sr.Peek() >= 0)
{
char c = (char)sr.Read();

if (c == '\r' || c == '\n') // EDITED
{
string command = new string(buffer.ToArray());
// process command
}
else if (c == '\b' && buffer.Count > 0)
{
buffer.RemoveAt(buffer.Count - 1);
}
else
{
buffer.Add(c);
}
}
}
15y ago
If you use ArrayList it is simple and easiest way. Easily you can remove /add the item in the ArrayList.
Frogleg15y ago
Use arraylist
using System.Collections;

ArrayList myAL = new ArrayList();
myAL.Add("Hello");
myAL.Add("World");