typedef enum

What is the output for the program given below

     typedef enum errorType{warning, error, exception,}error;

     main()

    {

        error g1;

        g1=1;

        printf("%d",g1);

     }

Answer

         Compiler error: Multiple declaration for error

Explanation

The name error is used in the two meanings. One means that it is a enumerator constant with value 1. The another use is that it is a type name (due to typedef) for enum errorType. Given a situation the compiler cannot distinguish the meaning of error to know in what sense the error is used:

    error g1;

g1=error;

    // which error it refers in each case?

When the compiler can distinguish between usages then it will not issue error (in pure technical terms, names can only be overloaded in different namespaces).

Note: the extra comma in the declaration,

enum errorType{warning, error, exception,}

is not an error. An extra comma is valid and is provided just for programmer’s convenience.

Blog Author: Vijay Kumar

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