I don't know what I'm doing wrong I'm stuck on this for the past two hours. Any help would be highly appreciated.
My code is the following:-
#include <stdio.h>
int* findLargest(int* arr,int size){
return &arr[size-1];
}
int main(){
int size=3;
int arr[3]={3,4,5};
int* largest=&arr[size-1];
int* largest2=malloc(100);
largest2=findLargest(*arr,size);
printf("%d",largest);
printf("%d",*largest2);
}
I get a garbage value when I execute.
Only pass arr to findLargest, this is already a pointer
largest2=findLargest(arr,size);
printf contents of largest, not the pointer itself
printf("%d\n", *largest);
Also, I'm not sure why you have the line:
int* largest2=malloc(100);
The malloc'd pointer is immediately lost in the next line when you assign to largest2 again.
I would also consider assigning size like so:
int size = sizeof(arr)/sizeof(arr[0]);
This is safer if you change the contents of arr in the future.
With all these changes main looks like:
int main()
{
int arr[3]={3,4,5};
size_t size = sizeof(arr)/sizeof(arr[0]);
int* largest=&arr[size-1];
int* largest2=findLargest(arr,size); // Only pass array to findLargest, this is already a pointer
printf("%d\n", *largest); // printf contents of largest, not the pointer
printf("%d\n", *largest2);
}
sizeof-operator evaluates to a size_t, not to an int.The problem here is this line
printf("%d",largest);
Where you're not de-referencing the pointer. Nor is there a space or new line after the value causing more confusion.
you can't edit address of pointer, you've to edit value of pointer
like this:
int * v = malloc(sizeof(int)); //WRONG
int n=54;
v=&n;
int * v = malloc(sizeof(int)); //CORRECT
int n=54;
*v=n;
Well, the problem was simple. Just in case someone runs into this confusion this can help.
The correct code is:
#include <stdio.h>
int* findLargest(int* arr,int size){
return &arr[size-1];
}
int main(){
int size=3;
int arr[3]={3,4,5};
int* largest=&arr[size-1];
int* largest2=malloc(100);
largest2=findLargest(arr,size);//Not findLargest(*arr,size)
printf("%d",*largest2);
}
findlargest.c:16:26: warning: passing argument 1 of ‘findLargest’ makes pointer from integer without a cast