Sunday, August 2, 2009

Pointer to a pointer in C programming?

can you please explain to me the advantages of using pointer to a pointer in C programming?.





I also dont know how i can use them.


try to give me an example.

Pointer to a pointer in C programming?
Here's the deal - pointers to pointers are the SAME as multidimensional arrays in any other language.





Consider this:


int[][] matrix;





This is a 2-d array of numbers, such as a reachability matrix for a graph. You need this 2-d array to perform operations such as finding the shortest path between 2 points, or finding the number of distinct paths, or any other graph-operation.





You can use pointers to pointers to simulate this kind of 2-d array. Look at this for more info:


http://computer.howstuffworks.com/c32.ht...
Reply:There are a number of applications the most common is to assign a ptr in a function.


e.g.





int assign_ptr(int **a)


{


*a = malloc(8);


return 1;


}


yeah it's a nonsense example but it shows the point.

flower menings

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