c# - Why don't we use new operator while initializing a string?

Question

I was asked this question in an interview: Is string a reference type or a value type.

I said its a reference type. Then he asked me why don't we use new operator while initializing the string ? I said because the c# language has a simpler syntax for creating a string and the compiler automatically converts the code into a call for the construcor of the System.String class.

Is this answer correct or not ?

Answer 1

Strings are immutable reference types. There's the ldstr IL instruction which allows pushing a new object reference to a string literal. So when you write:

string a = "abc";

The compiler tests if the "abc" literal has already been defined in the metadata and if not declare it. Then it translates this code into the following IL instruction:

ldstr "abc"

Which basically makes the a local variable point to the string literal defined in the metadata.

So I would say that your answer is not quite right as the compiler doesn't translate this into a call to a constructor.