将字符添加到空字符串 C#

Question

Ive got an empty string s = "";

Ive got a char b = '0';

char b is in a loop so changes after every, I want to keep adding that char b to the string s,

For example, after the first loop string s = "0" after second round s = "01"

In Java its simple to do that for an empty string with string s += char b; Couldnt find anything like that on C#, is there an easier way than building a string builder or making a dummy string?

Answer 1

What you describe works in C#:

string x = "";
x += 'Z';
Console.WriteLine(x); // Prints "Z"

Or in a loop:

string x = "";
char b = '@';

for (int i = 0; i < 10; ++i)
{
    ++b;
    x += b;

    Console.WriteLine(x); // Prints "A", then "AB", then "ABC" etc.
}

However, you should use StringBuilder for efficiency.

The same loop as above using StringBuilder :

StringBuilder x = new StringBuilder();
char b = '@';

for (int i = 0; i < 10; ++i)
{
    ++b;
    x.Append(b);

    Console.WriteLine(x); // Prints "A", then "AB", then "ABC" etc.
}

Answer 2

Easy, but not efficient (String s constantly re-creaing ):

  char b = '0';

  for (int i = 0; i < n; ++i)
    s += (Char)(b + i);

Better choice is to use StringBuilder :

  char b = '0';

  StringBuilder sb = new StringBuilder(n);

  for (int i = 0; i < n; ++i)
    sb.Append((Char)(b + i));

  s = sb.ToString();