What is the difference between “String” and “StringBuilder”?

The concepts of "String" and "StringBuilder" are similar to those in Java. Here are the differences between them in C#:

String is IMMUTABLE in C#.

• It means if you defined one string then you couldn’t modify it. Every time you will assign some value to it, it will create a new string.

StringBuilder is MUTABLE in C#.

• This means if any manipulation will be done on string, then it will not create a new instance every time.

Here's an example in C# to demonstrate the difference:

string name = "John";
name += " Doe"; // Creates a new string object

StringBuilder sb = new StringBuilder("John");
sb.Append(" Doe"); // Modifies the StringBuilder object directly

string finalName = sb.ToString(); // Converts the StringBuilder to a string

In this example, using the "+=" operator with strings creates a new string object when concatenating "John" and " Doe". On the other hand, StringBuilder allows direct modification of the string without creating additional objects, resulting in better performance when working with large amounts of text.