C++ compiler error c4430 “c++ doesnt support defau

问题:

Hi im trying to define an alias called USHORT.

    // *****************
// Demonstrates typedef keyword
#include <iostream>

typedef unsigned short int USHORT;  // typedef defined

main()
{
USHORT  Width = 5;
USHORT Length;
Length = 10;
USHORT Area  = Width * Length;
std::cout << "Width:" << Width << "\n";
std::cout << "Length: "  << Length << std::endl;
std::cout << "Area: " << Area;
}

I keep getting a compiler error saying:

Error 1 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\users\naqvi-home\documents\justit\c++\w1\cp1\list0304.cpp 8 1 ConsoleApplication3

Thanks

Ray

回答1:

It has nothing to do with your typedef. The problem is that you haven't given a return type for main:

int main()
{
  // ...
}

A function must have a return type. The main function must return int.

回答2:

I don't believe you need the extra int in the typedef, I thought from memory unsigned short (by default) is an int.

回答3:

You can easily look up the explanation for the error, by googling the error code. E.g. googling for 'C4430' would lead you here. The reason is, as others have stated, that you haven't declared the return type for main function.