I would like to know what the [i] is for and why my table is not displayed if I do not put it, thank you !

#include <stdio.h>

void affiche(int* tableau, int taille);

int main()
{
    int tableau[5] = { 12,15,50,20 };

    affiche(tableau, 4);

    return 0;
}

void affiche(int *tableau,int taille)

{
    int i;
    for (i = 0; i < taille; i  )`
    {
        printf("%d\n", tableau[i]); 
    }
}

CodePudding user response：

[i] is the C language syntax for array notation.

tableau is an array of 5 integers.

int tableau[5] = {12,15,50,20}

In memory tableau has 5 slots allocated to it due to the above declaration.

Slots 0 through 4 are your initialization values. Slot 5 is uninitialized (though modern c compilers might set this value to null or zero (0).

      tableau
       ----------------------- 
index | 0  | 1  | 2  | 3  | 4 |
       ----------------------- 
value | 12 | 15 | 50 | 20 | ? |
       ----------------------- 

inside function affiche(...) this statement

printf("%d\n", tableau)

tries to print to console a single integer (%d) followed by a newline (\n)

But tableau is an array of 5 integers.

So you need the array index to select a specific integer individually like this:

printf("%d\n", tableau[0])  // output: 12
printf("%d\n", tableau[1])  // output: 15
printf("%d\n", tableau[2])  // output: 50
printf("%d\n", tableau[3])  // output: 20
printf("%d\n", tableau[4])  // output: unknown, possible exception

or by function call to affiche(tableau, 4); which ends at index 3

void affiche( int *tableau, int taille)
{
    int i;

    for( i = 0; i < taille; i  ){
        printf( "%d\n", tableau[i] );
    }
}

Which outputs:

12
15
50
20