Object –> StringBuilder


var sb = new StringBuilder("string"); // string is optional.
var sb = new StringBuilder("string", initial_capacity);
var sb = new StringBuilder(initial_capacity, max_capacity);


  • Chars[index] — Return or set the character at index.
  • Length — Current number of characters in the StringBuilder.
  • Capacity — Number of characters that the StringBuilder can currently hold. This is increased dynamically.
  • MaxCapacity — By default, set to Int32.MaxValue. Can be overwritten.



These methods accept a string, substring, character array, or the string representation of a primitive data type:

  • Append("substr") — Append substr to the StringBuilder.
  • AppendJoin(sep, "str[]") — Concatenate str array with sep between each string and append to the StringBuilder.
  • AppendLine("substr") — Append substr and \r\n to the StringBuilder.
  • Insert(index, "str") — Insert str at index.
  • Replace("old," "new") — Replace old with new.


  • Clear() — Empties the StringBuilder and sets Length to 0.
  • Remove(index, n) — Removes n characters from StringBuilder starting at index.


.EnsureCapacity(n) — Ensure the capacity of the StringBuilder is at least n. If not, expand it.
.ToString() — Returns the built string.