I'm still confused. Can I do this?
int x[y[3]]
Array within array?
Is that the correct format?
Thank you!
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2dude, What language are you using? – DiverseAndRemote.com Dec 13 '12 at 21:48
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You don't need to, all you need to do is a two dimensional array. – DrinkJavaCodeJava Dec 13 '12 at 21:49
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Thank you redelman! Just what I needed – Amadeus Dec 13 '12 at 21:50
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7There should be a badge for baiting multiple heavily downvoted answers. – Mysticial Dec 13 '12 at 21:57
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http://stackoverflow.com/a/13672861/179910 – Jerry Coffin Dec 13 '12 at 22:05
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Assuming you can do this (depending on whether it's C or C++, and which particular standard), it's probably not doing what you think. It will get the value of `y[3]` (which hopefully has been defined), and use that to size `x[]`. It's not a 2-dimensional array, as noted by numerous others... – twalberg Dec 13 '12 at 22:06
3 Answers
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int x[y[3]]; is valid if y[3] is an integral constant expression, and it will declare an array of y[3] elements. Otherwise it’s invalid.
If you are looking for a 2D array, try the following:
#include <array>
std::array<std::array<int, 3>, 4> x;
If you want less pain to go through, you can look at Boost.MultiArray, as suggested by Cat Plus Plus.
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2Boost.MultiArray or bust. Or maybe some other multi-dim array implementation, but definitely not vector of vectors. – Cat Plus Plus Dec 13 '12 at 21:58
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Even with the assumption that y[3] is of an integer type (otherwise it makes no sense), VLA (variable length arrays) are not supported in c++. They are part of C99, but not c++. Therefore, your code is not good.
Some compilers do support VLA, but only as an extension.
BЈовић
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It would be something like this
int[,] myArray = new int[1][2];
myArray[0][1] = 1;
myArray[1][1] = 1;
Ben
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2That is not valid C++ syntax. If that compiles at all, it is because of some compiler extension. Also you're indexing outside the bounds of the array. – Praetorian Dec 13 '12 at 21:53
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@R.MartinhoFernandes http://chat.stackoverflow.com/transcript/message/6693430#6693430 – Etienne de Martel Dec 14 '12 at 05:04