String builder does not have a clear method to clear the contents of stringBuilder, but if we want to add a clear method in StringBuilder, use the following method in your utility class.
public static void Clear(this StringBuilder stringBuilder)
stringBuilder.Length = 0;
stringBuilder.Capacity = 16;
Benefit of this method is if we use same stringbuilder variable with clear the existing contents.
StringBuilder sb =new StringBuilder();
// If you want to clear the content of sb then
This should be provided by Microsoft by default because if we re-init the string builder variable every time when we want to clear the content it will take lots of memory.