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Quick Question: Pointer to a 2D array
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Hi, sorry if this has been asked before I did a search but couldn't find it.
How do I define a pointer to a 2D array? (I am trying to pass it into a function).
Thanks.
How do I define a pointer to a 2D array? (I am trying to pass it into a function).
Thanks.
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Join Date: Aug 2005
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A 2d character array?
or like this:
void foo(char* ay[][255] ) or like this:
void foo(char **ay) Last edited by Ancient Dragon; Aug 9th, 2008 at 4:31 pm.
Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.
Sorry, but
Probably, coveredinflies wants to pass an array as a function argument so right example is most likely
But it's not the same as
A pointer to an array is a funny thing in C and C++. Array name is implicitly converted in a pointer in all contexts except argument of sizeof operator. So no need in pointers to arrays.
But we can't pass 2D array declared as a[...][...] in the second foo because of its argument type is a pointer to a pointer to char, but not an implicit pointer to 2D array with 255 columns...
char* ay[][255] declares 2D array of pointers to char.Probably, coveredinflies wants to pass an array as a function argument so right example is most likely
C++ Syntax (Toggle Plain Text)
C++ Syntax (Toggle Plain Text)
But we can't pass 2D array declared as a[...][...] in the second foo because of its argument type is a pointer to a pointer to char, but not an implicit pointer to 2D array with 255 columns...
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>>Sorry, but char* ay[][255] declares 2D array of pointers to char.
You are right -- I should not have included the star.
We don't know how the OP declared the 2d array, so it could be either method.
You are right -- I should not have included the star.
We don't know how the OP declared the 2d array, so it could be either method.
Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.
It's impossible to declare 2D array which can be passed as type** if a declarator does not know "how to define a pointer to a 2D array". He/she must declare an array of pointers then fill the array with proper pointers to 1D arrays and so on... It's impossible...
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Join Date: Aug 2005
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Impossible? I would call the below a 2d array.
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Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.
It seems you don't understand my previous post.
I never said that it's impossible for you (and me
)...
I never said that it's impossible for you (and me
)... In the true sense of the word(s) "2D array" a construct with array of pointers is not C/C++ 2D array.
Thanks this is what I needed. Pretty obvious in hindsight. Sorry for any ambiguity in original post.
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