Thread: Array problems

Okay, I want to make a program that needs 5 grades to be input, and then show the 5 inputted grades after. The problem is when using a for loop statement for the scanf, it always loop 6 times.
Any idea?

Code:

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


int main()
{
    int grade[4],average=0,cnt=0;




    for(cnt=0;cnt<=4;cnt++)
    {
        scanf("%d ", &grade[cnt]);
    }
printf("\n\n");
    for(cnt=0;cnt<=4;cnt++)
    {
        printf("%d\n", grade[cnt]);
    }
 return 0;
}

Also, nevermind the average variable, I'll be using that after I solve it.

You only have room for 4 elements in grade. Make it 5.
Also, the common idiom for a for loop is:

Code:

for (cnt = 0; cnt < 5; cnt++)

instead of cnt <= 4.

First, make sure your code is consistently indented - it should look more like this:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
 
int main()
{
    int grade[4],average=0,cnt=0;
 
    for(cnt=0;cnt<=4;cnt++)
    {
        scanf("%d ", &grade[cnt]);
    }

    printf("\n\n");
    
    for(cnt=0;cnt<=4;cnt++)
    {
        printf("%d\n", grade[cnt]);
    }
 
    return 0;
}

---

Code:

int grade[4]

This declares an array with 4 elements, not 5.

Code:

for(cnt=0;cnt<=4;cnt++)

The more common idiom is to use less-than here:

Code:

for(cnt=0;cnt<5;cnt++)

This allows you to used a named constant in lieu of a magic number:

Code:

#define NUM_GRADES  5

// ...

int grade[NUM_GRADES];

// ...

for(cnt=0; cnt<NUM_GRADES; cnt++)
    // ...

---

Code:

scanf("%d ", &grade[cnt]);

That space after %d is causing the unexpected behavior you are seeing - try deleting it.

---

Also, "conio.h" is a non-portable and non-standard header, so you shouldn't include it - especially since you're not using any functions from it.

Oh, the space after the "%d" is the problem. Thank you! That fixed the problem.
Any idea why space after %d made the difference?