String.Empty versus "" - The real deal

re: String.Empty versus "" - The real deal

Jamal Mavadat — Tue, 01 Jul 2008 05:16:53 GMT

OOPS!!! Sorry matey :)

Anyway, the constant literal case ("") goes through internal AppDomain (well Module actually) hash-table (string interning) which is slower during JIT compilation. This is supposed to happen once for every "" usage unless exclusively optimised which makes it implementation-specific though.

At the other hand, the static field alternative (String.Empty) goes through the same process only once for the whole AppDomain speeding up JIT compilation!

Both gains and pains are not enough making you ponder; there are lots of performance gains available out there by clever architectural decisions and ...

re: String.Empty versus "" - The real deal

Senthil — Mon, 30 Jun 2008 15:31:50 GMT

Well no, it's not the call instruction, but the mov instruction just before it that is the assignment. It moves the reference to the string to ecx and calls DoNothing.

re: String.Empty versus "" - The real deal

Jamal Mavadat — Mon, 30 Jun 2008 09:43:23 GMT

No surprise as the "call" instruction is not the real assigment you were looking for to compare performance. You should be continuing drilling down intro the JIT-generated code to find out what happens!