About C # compiler guaranteed variables must initialize rules conjecture

There are two situations:

First case:

usingSystem;namespacewrox{ Public classProgram {Static voidMain (string[] args) {            intindex; if(true) {Index= -;                        } Console.WriteLine (index);                    Console.readkey (); }    }}

Second case:

usingSystem;namespacewrox{ Public classProgram {Static voidMain (string[] args) {            intindex; BOOLIstrue=true; if(IsTrue = =true) {Index= -;                        } Console.WriteLine (index);                    Console.readkey (); }    }}

In both cases, the first case compiles normally, and the second fails to compile, prompting the index variable to be uninitialized.

The reason for this individual guess analysis is as follows:

In the first case, when the compiler executes to the IF statement, because true is a constant, it can be judged at compile time that the branch of the index initialization will go, so the compilation succeeds.

In the second case, when the compiler executes to the IF statement, because IsTrue is a variable, the compiler cannot get its value at this point. Therefore, the compiler is used to determine whether the index is initialized or not, to determine if all the branches that might be overwritten are initialized with the index variable. Because the index is only initialized in the if branch at this time, an error is compiled at this point.

To verify the above inference, the code can be modified as follows:

usingSystem;namespacewrox{ Public classProgram {Static voidMain (string[] args) {            intindex; Const BOOLIstrue=true; if(IsTrue = =true) {Index= -;                        } Console.WriteLine (index);                    Console.readkey (); }    }}

The above code is compiled correctly, so this inference can be supported.

About C # compiler guaranteed variables must initialize rules conjecture