String vs. StringBuilder

Question

I understand the difference between String and StringBuilder (StringBuilder being mutable) but is there a large performance difference

Answer 1

Yes, StringBuilder gives better performance while performing repeated operation over a string. It is because all the changes are made to a single instance so it can save a lot of time instead of creating a new instance like String.

String Vs Stringbuilder

• String

  1. under System namespace
  2. immutable (read-only) instance
  3. performance degrades when continuous change of value occures
  4. thread safe

• StringBuilder (mutable string)

  1. under System.Text namespace
  2. mutable instance
  3. shows better performance since new changes are made to existing instance

Strongly recommend dotnet mob article : String Vs StringBuilder in C#.

Related Stack Overflow question: Mutability of string when string doesn't change in C#?.