Arrays in C

[prathiyus]

just writing and testing the code using arrays,

int main()
{   int i,n;


    int arr[14];

    printf("\nEnter the array ",n);
    scanf("%d",&n);
    int lastindex =  n-1;
    int *l;
    l = &lastindex;
    for(i = 0;i<n;i++)
    {
        scanf("%d",&arr[i]);
    }
    for(i = 0;i<n;i++)
    printf("\n%d\n",arr[i]);
    printf("%d",*l);
    //arr[i] = lastindex + 2;
    //printf("\n%d",arr[i]);
    if(arr[lastindex[arr]]  < lastindex)
    {
        printf("\n %d",arr[lastindex[arr]]);
        printf("\nright");
    }
    else
    {   printf("\n%d",lastindex);
        printf("wrong");

    }
}

//output
Enter the array 5
5
4
3
2
1

5

4

3

2

1
4

4 wrong
arr[lastindex[arr]]
lastindex[arr] will be 4
arr[4]= 1
1 < 4 is true so it has to print right,but its printing wrong
whats the wrong in the code

[Ancient Dragon]

arr[4]= 1
1 < 4 is true so it has to print right,but its printing wrong

Yes, but that isn't what is being compared. arr[1] is 4

[prathiyus]

couldn't get you,can you explain it please

[Ancient Dragon]

lastindex[arr] is the same thing as arr[lastindex], which is 1, not 4. So the comparsion can be rewritten like this:
if(arr[arr[lastindex]] < 4)

Now, start from the innermost expression arr[lastindex] which is 1, then evaluate arr[1] which is 4.

[prathiyus]

got it,Thanks

[Ancient Dragon]

BTW, don't use index[arr] because that form is rarely, if ever, used in real life. If you intend to index an array, then do so like this: arr[index]

[prathiyus]

but to how to write the code to return the lastindex first

[Ancient Dragon]

you mean you want to display the data in reverse order, such as 1 2 3 4 5 instead of 5 4 3 2 1? You already have a pointer named l, just use it

int* l = &arr[lastindex];
while( l > arr )
{
   printf("%d\n", *l);
   --l;
 }

or you could do this:

while( lastindex >= 0)
{
   printf("%d\n", arr[lastindex]);
   --lastindex;
}

[prathiyus]

i need to return the lastindex of the array and then element in the index,how to do that

[prathiyus]

no,not in reverse order,say n is 5 and the last array index is 4,and then have to print the element in the last index

[Ancient Dragon]

then just print arr[lastindex] (assuming the value of lastindex == 4)

[prathiyus]

how to write in code ,to return the last index and the element in the lastindex

[deceptikon]

Dude, go read a book on C. You're asking for something so trivial that I can't imagine anything other than total ignorance as the cause. This forum is not for holding your hand and teaching you from scratch.

[Ancient Dragon]

how to write in code ,to return the last index and the element in the lastindex

lastindex is not an array, so your question makes no sense.