Question

does the following code create 3 new strings each time the method is called and evaluated to true or is the compile smart enough to compile the right hand side strings into constants?

if (somestring == "Test" || someString == "Test1")
{
   ...
   NotifyPropertyChanged("Name");
}

Answer 1

They are literals, which means that they are loaded with the ldstr opcode, i.e.

ldstr "Test1"

The impact of this is that: anything that goes through ldstr is automatically interned, so, you can do this:

string x = "abc";
string y = "abc";
bool sameInstance = ReferenceEquals(x,y); // true

So: yes, the first time that method is used, the literals "Test", "Test1" and "Name" may be created, but only once. After that, the same existing string instances are used. This is guaranteed by ldstr:

The Common Language Infrastructure (CLI) guarantees that the result of two ldstr instructions referring to two metadata tokens that have the same sequence of characters return precisely the same string object (a process known as “string interning”).