how to create an array of enum data type?

This is a discussion on how to create an array of enum data type? within the C++ Programming forums, part of the General Programming Boards category; Hi I want to create an array of my own defined data type. Does anyone have idea how to do ...

  1. #1
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    Question how to create an array of enum data type?

    Hi

    I want to create an array of my own defined data type. Does anyone have idea how to do that: Example
    User defined data type is:

    Code:
    typedef enum{ 
    CHIP, 
    BOUNDARY, 
    BOARD, 
    CHAIN 
    } test_dft;
    Now I want to declare array of my data type. Example:

    Code:
    test_dft mode1[2] = {CHIP, CHAIN};
    I am declaring the array as above. I know that by default the enum data type is integer. First question is that, Is it ok to declare an array like this? My another question is that how would my compiler knows that the array I declared corresponds to the exact value as shown in the user defined data type? example CHAIN defined in array corresponds to the value of CHAIN in the user defined data type.

  2. #2
    and the hat of wrongness Salem's Avatar
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    Have you tried it?

    Everything seems OK so far.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

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    Quote Originally Posted by debugg View Post
    My another question is that how would my compiler knows that the array I declared corresponds to the exact value as shown in the user defined data type? example CHAIN defined in array corresponds to the value of CHAIN in the user defined data type.
    Because you declare the array "model" to contain elements of type "test_dft". Check it for yourself and add init. values not defined by your enumeration and you'll see the compiler complains.

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    well I am still running it as I am running it in a big project but I still didnt know if my how my compiler knows that the array I declared corresponds to the exact value as shown in the user defined data type? example CHAIN defined in array corresponds to the value of CHAIN in the user defined data type. Does my compiler knows automatically? I am asking this question because I declared the array in different class and my user defined data type is defined in different class.

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    Quote Originally Posted by debugg View Post
    my user defined data type is defined in different class.
    I'm not sure to follow you... your type should be defined in only one place.

  6. #6
    and the hat of wrongness Salem's Avatar
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    > well I am still running it as I am running it in a big project but
    But why haven't you bothered to create a separate small project with a 10-line program to test your ideas?

    Code:
    int foo = 1;
    int bar[] = { 1, 2 };
    if ( 1 == 1 )
    if ( foo == 1 )
    if ( bar[0] == 1 )
    All works the same as
    Code:
    test_dft foo = CHIP;
    test_dft bar[] = { CHIP, CHAIN };
    if ( CHIP == CHIP )
    if ( foo == CHIP )
    if ( bar[0] == CHIP )
    > I am asking this question because I declared the array in different class and my user defined data type is defined in different class.
    Regardless of where you declare it, the compiler will still need visibility of it (via say a header file), and then everything will line up correctly.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

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    Thanks a lot everyone. It worked for me..

  8. #8
    C++まいる!Cをこわせ! Elysia's Avatar
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    FYI,
    Code:
    typedef enum{
    CHIP,
    BOUNDARY,
    BOARD,
    CHAIN
    } test_dft;
    This is the old C way.
    Code:
    enum test_dft
    {
    	CHIP,
    	BOUNDARY,
    	BOARD,
    	CHAIN
    };
    This is the C++ way of declaring enums.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  9. #9
    Registered User whiteflags's Avatar
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    That's misinformation Elysia. C does not require enums to be typedef'd. I do have doubts that was the point. No matter what your point actually was, though, it compiles either way.

  10. #10
    C++まいる!Cをこわせ! Elysia's Avatar
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    I didn't say it didn't compile. I said it was the old C way, and I said that because you had to do that or do a typedef later on to avoid having to put "enum" before the type name, but that's not required in C++.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

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