C - How to insert an integer value into an array

Question

I have a problem with this code:

main :

#include <stdio.h>
#include <stdlib.h>
#include "Function.h"
int main()
{

int B[9]; 

saisie_B_M(&B[9]);

return 0;

}

Function.c

void saisie_B_M(int B[9])
{

int i;

for(i=0; i<8; i++)
{
    printf("Une cellule morte ayant %d voisins sera t-elle morte ou vivante à la génération suivante ? \n", i);
    scanf("%d", &B[i]);
        }
    }

function.h

#ifndef Function_H_INCLUDED
#define Function_H_INCLUDED
void saisie_B_M(int B[9]);
#endif // Function_H_INCLUDED

The principle is simple, it is an array of 9 and I just return a value in each cell of the table. But there is a bug at the end and I don't know why the compiler does not show a message.

Answer 1

The problem is when you call your function with

saisie_B_M(&B[9]);

It should be

saisie_B_M(B);

In the first case, you give an array but starting at the 9th offset B[9] . So your function will start iterating at 9th then 10th, 11th, 12th... the behaviour is undefined.

Answer 2

扩展@Miguel Prz的答案，如果您想从第一个元素开始，则需要传递对数组中第一个元素的引用： saisie_B_M(&B[0])或只使用saisie_B_M(B) 。

Answer 3

Arrays in C are zero-indexed, so B[9] has elements in the 0..8 range. This is not valid:

saisie_B_M(&B[9]);

if you want to pass the pointer to the last element yo need to use:

saisie_B_M(&B[8]);

but it seems you need the complete array, so pass &B[0] (or simply B) to saisie_B_M function. Also your "for" loop should be changed to this:

for(i=0; i<9; i++) {
/* ... */
}