Question

As we all know strings are implicitly instantiated, meaning that we don’t have to use new in order to get a reference to an object of one.

Because of this it was always my belief that the framework is taking care of this, and hence I would get identical IL if I did something like this:

String first = new String(new char[] {'a'});
string second = "a";

However it appears that the first line is done using newobj instance void [mscorlib]System.String::.ctor(char[])
and the second ldstr "a".

So in order to obtain a string reference, does ldstr internally call newobj and where can I see the specification / details to back this up?

Answer 1

ldstr gives you the reference to the literal string as per the documentation (remember literal strings are interned per default, so they are only created once). The first statement creates a regular instance of string using the newobj instruction as expected.