C-to-C + + upgrade

All variables in C + + can be defined when they are needed.

Variables in the C language must be defined at the beginning of the scope.

Register keyword requests the compiler to store local variables in registers

Cannot get the address of register variable in C language

The address C + + compiler that can get the register variable in C + + has its own optimization method, so almost no register

In the C language, it is legal to repeatedly define multiple global variables with the same name, and C + + does not allow it.

Strengthening of the struct keyword

-A struct in the C language defines a set of variables

-Strut defined identifiers in C language are not a new type

Structs in-c++ are used to define a completely new type

The C language requires typedef to define new types of structs, and C + + is not required.

The type of claim that all identifiers in C + + must display

The default type in C is not legal in C + +

is int f () different from int f (void)?

In the C language

-int F () represents a function that returns a value of int that accepts arbitrary arguments

-F (void) indicates an parameterless function with a return value of int

In C + +

-int f () and int f (void) have the same meaning

An parameterless function that represents a return value of int

C-to-C + + upgrade