Thread: HELP NEEDED: Count the number of element of array of pointer inside function

I need help for calculate the number of element of the array of pointer inside a function. But I always get a return value of 1 element. Is there any way to program it to get the correct value? Thank you very much.

Code:

#include "stdafx.h"
#include <stdlib.h>

unsigned int read_file(char*my_filename[])
{
	return	sizeof(my_filename)/sizeof(my_filename[0]);
}

int _tmain(int argc, _TCHAR* argv[])
{
	unsigned int num_file=0;
	char * my_filename[]={"a","b","c"};
	num_file=read_file(my_filename);
	printf("%d\n",num_file);
	system("pause");
	return 0;
}

I need help for calculate the number of element of the array of pointer inside a function.

This is not possible. When you pass an array to a function it decays to a pointer and you loose all size information. You need to either keep track of the array size, or compute the size in the function where the array is declared. You should always pass the size of the array into the function as another parameter.

Code:

unsigned int read_file(char*my_filename[], size_t array_size);

int main(int argc, char* argv[])
{
    unsigned int num_file=0;
    char * my_filename[]={"a","b","c"};
    size_t array_size = sizeof(my_filename)/sizeof(my_filename[0]);
    num_file=read_file(my_filename, array_size);
    printf("%d\n",num_file);

    return 0;
}

Jim

Thanks jimblumberg. I have try this out. I know that doing in main can work for it. But I wonder is there another way to do it? Or string is it possible for it?

Thanks for this suggestion. I learned some new stuff