can you use variables with and array....

This is a discussion on can you use variables with and array.... within the C++ Programming forums, part of the General Programming Boards category; ok so ive tried doing this but it doesnt seem to work... I'm coding a game and whn i code ...

  1. #1
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    can you use variables with and array....

    ok so ive tried doing this but it doesnt seem to work... I'm coding a game and whn i code the output it would be a lot easier just to have a for() statement that would loop until it equaled a certain alue... can this be done.. 2-d array, also it compiles fine but when it gets to the part that it uses the array wih variable my i get a windows error that says program is has stopped working
    thanks cj
    somthing like this...
    Code:
    //not actual code
    int x;
    int y;
    array[x][y];
    cout<< array[x][y];
    Last edited by jamort; 12-06-2009 at 05:06 PM.

  2. #2
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    There are two issues in your example code. First, you aren't allowed to use variables like x and y as the size of your array in standard C++. It might work on your compiler if you use g++ because they allow it as an extension. If that's the case you can use it, but be aware it won't work on all compilers.

    The standard way to do a dynamic array like that is to use a vector (or in this case a vector of vectors). They are designed to have a size that is determined at runtime. If you're not able or not allowed to use vector, you can also use a regular array with a max size, then just keep track of how many actual values you are using.

    Your example code doesn't initialize x and y, and it uses array[x][y] which is out of bounds of the array. I assume you're aware of those issues, at least the first, but it sounds like you're tying to figure out how to loop through all values? For a 2-D array, you just need a nested for loop. The first starts at zero and runs while the index is less than x, the second runs from 0 to y.

  3. #3
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    yeah... meant that i already had the size of the array.. and was just going to use the x and y in the for loop... which works is really good being that it cut out about 400-500 lines of code... by the way im working on a connect four game

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