Which is more efficient: hard coded strings in code --or-- reusing a string reference?

Question

was wondering which of the following options is more efficient. Any suggestions?

Listing 1

string header = "Header 1"; // create a string variable and reuse
client.AddMessage(header, ...);
client.AddMessage(header, ...);
client.AddMessage(header, ...);
client.AddMessage(header, ...);
client.AddMessage(header, ...);
...

Listing 2

client.AddMessage("Header 1", ...); // hard code the string in each call
client.AddMessage("Header 1", ...);
client.AddMessage("Header 1", ...);
client.AddMessage("Header 1", ...);
client.AddMessage("Header 1", ...);
....

Answer 1

You should probably not care about this kind of (possible) micro-optimization : what matters, here, is maintenability :

• do you have only one string ?
• or can you have several distinct values, one day or another ?

(The compiler should optimize that for you, anyway, I suppose)

Answer 2

Strings are interned in the .NET world, so either one will work the same way.

In other words - it makes no difference in regards to performance.

As for maintainability - if you need to change the header name, option 1 is better (DRY).