Why does my code give me nothing as result

Question

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int list[]; /*creating an arry call list*/
int main()
{
    srand(time(NULL));
    void element()/*creating the first element function*/
    {
        int i; 
        for (i=0; i<100; i++){
            list[i] = 100+rand()%900  ;
        }

        for (i=0; i<100; i++){
            printf("%d", list[i]); 
        }
    }
    return 0;
}

I don't know why does it give me nothing as result, the purpose of the code is to generate 100 random numbers and puts the number into the array.

Also, remember that arrays in C have a *fixed size*. Creating an empty array is not valid. — Some programmer dude, Jun 24 '17 at 23:58
It shouldn't give nothing. It should throw a score of errors and the kitchen sink at you during compilation. — cs95, Jun 24 '17 at 23:59
For starters I would recommend [finding a good beginners book](http://stackoverflow.com/questions/562303/the-definitive-c-book-guide-and-list). Then read your way up to and including the chapters about pointers, arrays and *dynamic memory allocations*. — Some programmer dude, Jun 25 '17 at 00:01
the posted code contains a second function contained within the `main()` function. That is not valid code. (although `gcc` does have an 'extension') It would be much better (and massively more portable) to declare a second function and have the `main()` function call that second function at the appropriate time. — user3629249, Jun 26 '17 at 03:33
this: `int list[]; /*creating an arry call list*/` is not a valid way to declare an array. Suggest: `int list[1]; /*creating an arry call list*/` — user3629249, Jun 26 '17 at 03:35
even with the incorporation of my prior comment about the declaring of 'list[]', accessing anything beyond the first element is undefined behavior and can lead to a seg fault event. Given the rest of the code, strongly suggest using: `int list[100];` — user3629249, Jun 26 '17 at 03:37

score 0 · Accepted Answer · answered Jun 25 '17 at 00:33

You need to make a couple of changes:

1)You can do it everything inside the main function unless you need to move it.

2)Remember you need to set the array size (in this case 100).

3)If you use a function you need to declare the prototype before the main function.

4)You can use the same for loop once to iterate and print the numbers.

  #include <stdio.h>
  #include <stdlib.h>
  #include <time.h>

  int main()
 { 
     int list[100]; /*creating an arry call list*/
     srand(time(NULL));

   int i; 
  for (i=0; i<100; i++){
  list[i] = 100+rand()%900  ;
    printf("%d \n", list[i]); 
}

}

but why it runs under the main function but when i create the function element it doesn't work ? — fearthewild, Jun 25 '17 at 01:34

score 0 · Answer 2 · answered Jun 25 '17 at 02:20

If you want a function to be executed you must invoke that function. Without making an explicit call a function cannot be executed.

You must also provide the array size in your code before compilation.

Alternatively you can also choose to use the variable length array feature in C which allows you to specify the array size at run time instead of forcibly specifying before compilation.

Why does my code give me nothing as result

2 Answers2