Thread: pointer to array

hi
please help me with the concept of pointer to an array and also macros.
regards
Mrunal

i am not an expert...but i KNOW that when we tell "there is apointer to an array we mean a pointer to the first element of the array, the first cell if you want".

for example: if we have an array of integers size 10.

Code:

int A[10];

and a pointer: *ptr

Code:

int *ptr;

this part:

Code:

 ptr = &A[10]

simply "strores" to the pointer the beginning of the array. the A[0] cell.

However what i told you is somehow general can you be more specific to what do you want to do?

Originally Posted by brack

i am not an expert...but i KNOW that when we tell "there is apointer to an array we mean a pointer to the first element of the array, the first cell if you want".

for example: if we have an array of integers size 10.

Code:

int A[10];

and a pointer: *ptr

Code:

int *ptr;

this part:

Code:

 ptr = &A[10]

simply "strores" to the pointer the beginning of the array. the A[0] cell.

However what i told you is somehow general can you be more specific to what do you want to do?

If you are having array A of size 10, you can access from A[0] to A[9], a[10] will be a garbage.

Code:

ptr = &A[10];

here ptr will store address of A[10] cell, i.e. of 11th cell which will be having garbage.

there are two ways
1.

Code:

 ptr=&A[0];

2.

Code:

  ptr=A;

As in 2nd case, name of array gives base address of array i.e. A[0]

Thanks ,everyone .I did it,this is my solution

Code:

void swapColumns(double a[][6],int row,int col,int fswap,int sswap)
 {
    int i;
    double hold,*px;
    px=a;
   for (i=0;i<row ;i++) 
   {  
    hold=*(px+i*col+fswap); 
    *(px+i*col+fswap)=*(px+i*col+sswap);
    *(px+i*col+sswap)= hold; 
   }  
  }

Hi,
well,
there's some problem with your coding...
look this when i compile them >
http://i235.photobucket.com/albums/e.../untitled5.jpg
i don't think that px = a; is a valid command