使用指针从一个数组复制到另一个数组

Question

I've written some code to try and copy an array and then return a pointer to that new, copied array.

#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//// Returns a pointer to a freshly allocated array that contains the
// same values as the original array, or a null pointer if the
// allocation fails. The caller is responsible for freeing the array
// later.

uint8_t* copy( const uint8_t array[], 
           unsigned int cols, 
           unsigned int rows )
{
  uint8_t* dest = malloc(rows*cols*sizeof(uint8_t));
  int i;
  for (i=0; i<rows*cols;i++)
    {memcpy(&dest[i], &array[i], sizeof(array[0]));}

  if (dest!=NULL)
    {return *dest;}
  else 
    {return NULL;}
}

// Print destination array 
int main(){
int i=0;
const uint8_t cols=3;
const uint8_t rows=2;
const uint8_t dest[rows*cols];
const uint8_t array[rows*cols];

array[rows*cols]={1,2,3,4,5,6};

dest=copy(array, cols,rows);

for (i=0; i<rows;i++)
        {printf("%d ,",dest[i]);}

return 0;
}

But I'm getting these compile errors

Testing_code.c: In function 'copy':
Testing_code.c:22:6: warning: return makes pointer from integer without a cast [enabled by default]
     {return *dest;}
      ^
Testing_code.c: In function 'main':
Testing_code.c:35:18: error: expected expression before '{' token
 array[rows*cols]={1,2,3,4,5,6};
                  ^
Testing_code.c:37:1: warning: assignment of read-only location 'dest' [enabled by default]
 dest=copy(array, cols,rows);
 ^
Testing_code.c:37:5: error: incompatible types when assigning to type 'const uint8_t[(sizetype)((int)rows * (int)cols)]' from type 'uint8_t *'
 dest=copy(array, cols,rows);
     ^

Im new to using pointers so I hope I'm doing them correctly. I've tried to allocate memory in hemp for the dest array, copy the values of array into dest and then rerturn a pointer to dest.

Answer 1

尝试返回 dest 而不是 *dest