C# adding string to another string [duplicate]

Question

Possible Duplicate:
What's the best string concatenation method using C#?

I have a variable :

string variable1;

And I'm trying to make something like this :

for (int i = 0; i < 299; i += 2)
        {
            variable1 = variable1 && IntToHex(buffer[i]);
        }

IntToHex is a string function, so the result of the "IntToHex(buffer[i])" will be string. But it comes up to an error saying I cannot use &&. Is there any solution to add a string to another string? Thanks!

Answer 1

Just use the + operator:

variable1 = variable1 + IntToHex(buffer[i]);

You also need to initialise variable1:

string variable1 = string.Empty;

or

string variable1 = null;

However consider using a StringBuilder instead as it's more efficient:

StringBuilder builtString = new StringBuilder();

for (int i = 0; i < 299; i += 2)
{
    builtString.Append(IntToHex(buffer[i]));
}

string variable1 = builtString.ToString();

Answer 2

In C#, simply use a + to concatenate strings:

  variable1 = variable1 + IntToHex(buffer[i]);

But more important, this kind of situation requires a StringBuilder.

    var buffer = new StringBuilder();
    for (int i = 0; i < 299; i += 2)
    {
        buffer.Append( IntToHex(buffer[i]) );
    }

    string variable1 = buffer.ToString();

For loops of 100 or more this really makes a big difference in performance.