Question about ENUM

This is a discussion on Question about ENUM within the C++ Programming forums, part of the General Programming Boards category; hello there, i have something confused. if i type this Code: enum days { sun, mon, tue, wed, thu, fri, ...

  1. #1
    Registered User
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    May 2012
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    Question about ENUM

    hello there,

    i have something confused.

    if i type this
    Code:
     enum days { sun, mon, tue, wed, thu, fri, sat };
    then typing ;
    Code:
     cout << days(1);
    should not result in outputing "mon" ?
    when i do this it outputs the number '1' instead of the day behind this number (sun=0, mon=1)

    why is that?

  2. #2
    a_capitalist_story
    Join Date
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    Posts
    2,650
    No. An enum is just a nice way of representing integer values. You're aliasing sun for 0, mon for 1, etc.

    What you would need to do here is have an array of the string values of the days, like this:

    Code:
    const char * const dayVals[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
    and then you can use the enum to index into this array to get the name:

    Code:
    cout << dayVals[mon] << endl; // prints "Mon"

  3. #3
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    Quote Originally Posted by rags_to_riches View Post
    No. An enum is just a nice way of representing integer values. You're aliasing sun for 0, mon for 1, etc.

    What you would need to do here is have an array of the string values of the days, like this:

    Code:
    const char * const dayVals[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" };
    and then you can use the enum to index into this array to get the name:

    Code:
    cout << dayVals[mon] << endl; // prints "Mon"

    do i have to cout << dayVals[mon] ?
    what if i want to print all the days in a loop, can't it be printed by dayVals[i] for e.g. ?

  4. #4
    Registered User antred's Avatar
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    Quote Originally Posted by Jonathan Yaniv View Post
    do i have to cout << dayVals[mon] ?
    Yes.

    Quote Originally Posted by Jonathan Yaniv
    what if i want to print all the days in a loop, can't it be printed by dayVals[i] for e.g. ?
    Yup. You can just run a for-loop over your dayVals array and use the loop index to access individual array elements. Beware that this will not work if your enum definition contains "holes", i.e.

    Code:
    enum Foo
    {
        Bar,
        Blah,
        Meep = 34,  // <-- hole! enum values are not contiguous
        Woosh
    };
    In such a case, your best bet may be writing a function to print enum values:

    Code:
    void printFoo( Foo enumVal, std::ostream& out )
    {
        switch ( enumVal )
        {
        case Bar:
            out << "Bar";
            break;
            
        case Blah:
            out << "Blah";
            break;
            
        case Meep:
            out << "Meep";
            break;
            
        case Woosh:
            out << "Woosh";
            break;
            
        default:
            out << "UNRECOGNIZED Foo enum with integer value " << enumVal << "!";
        }
    }

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