How can i set up a constructor to dynamical manipulate an array?

[devonrevenge]

im having a lot of trouble doing something like so...can you see what im trying to do, where can i find the rules of declaring arrays in class and their member initializers

struct node
{
char symbol[int x][int y];
node *link;
node ():link(NULL){}
node (symbol [x][y],node *link): symbol[x][y](symbol [x][y]), link (link) {}

};

[guestgulkan]

Two things (at least):

1. in C++, the dimensions for an array should be a constant - so
char symbol[int x][int y]; is incorrect (although GCC might allow it - it is incorrect to the the c++ standard).

2. In C++ - it has never been permitted to assign arrays
to each other (and certainly not initialise a local array from an array passed as a function parameter which as we know is actally passed as a pointer)
- so you cannot initialise the array the way you are attempting

[devonrevenge]

i realised that i couldnt initialize my arrays in this way when my compiler told me it was wrong, i sure would love to know how to, can you see though what i was trying to do? i was trying to get it so could manage the saze of the 2d array dynamicaly; im finding it hard to get an example

struct node
{
char array [6] [6];
node (): array[6][6] (array [6] [6]){}
};

then why does the above not workify?

[freddy92]

So do you just want to set the size of the array dynamically, or do you want to copy an existing array into your new array dynamically?

[devonrevenge]

i would love to see an example of both, that would make everything else i have planned for the code more flexible but copying an existing array into the array is the main aim (both would mean i could copy any 2d array in)

[devonrevenge]

la BUMP

[Imadatobanisa]

You may use a pointer with operator new[size];
But be careful. Using pointer is extremely dangerous.
I recommend you use vector. This is the best way to go.

[Darkmaster]

But be careful. Using pointer is extremely dangerous.

yes it can blow up your pc and set your house on fire.


probably the problems with your array declaration is, that x and y get set during runtime. you cant declare arrays during runtime, they need a fixed size.
to get rid of this problem have a look at: http://www.fredosaurus.com/notes-cpp/newdelete/50dynamalloc.html

or use http://www.cplusplus.com/reference/vector/vector/

[devonrevenge]

great :D