StringBuilder append same char multiple times

Question

Is there a fast way to append a StringBuilder multiple times in C#? Of course I can write my own extension to append in loop, but it looks ineffective.

Answer 1

There is already an Append overload that accepts char value and int repeatCount:

char c = ...
int count = ...
builder.Append(c, count); 

or more simply (in many cases):

builder.Append(' ', 20);

Answer 2

You can use string constructor

sb.Append(new String('a', 3)); // equals  sb.Append("aaa")