How does StringBuilder's capacity change?

Question

When I have an empty StringBuilder with a capacity of 5 and I write \"hello, world!\" to it, does the C# standard specify the new capacity of the StringBu

Answer 1

The C# standard will not specify the behavior of a BCL library class as it has nothing to do with the language specification.

As far as I know the actual behavior is not defined in any specification and is implementation specific.

AFAIK, The MS implementation will double the capacity once the current capacity has been reached.

See this and this previous SO questions.

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Update:

This has been changed in .NET 4.0. as described by Hans in his answer. Now ropes are used, adding additional 8000 characters at a time.

MSDN, however is very careful to point out that the actual behavior is implementation specific:

The StringBuilder dynamically allocates more space when required and increases Capacity accordingly. For performance reasons, a StringBuilder might allocate more memory than needed. The amount of memory allocated is implementation-specific.