Example of Function in C

Question

I just start to study functions in C and this stopped me. I want to write a function that searches for an element in a vector of SIZE elements. Here's the code:

#include <stdio.h>
#define SIZE 10

int find(int vet[], int SIZE, int elem);

int main()
{
    int vett[SIZE] = {1, 59, 16, 0, 7, 32, 78, 90, 83, 14};
    int elem;

    printf ("Imput the element to find: ");
    scanf  ("%d", &elem);

    find(vett[SIZE], SIZE, elem);

    if (find == 1)
        printf ("\nI find the element!");
    else if (find == 2)
        printf ("\nI did not find the element!");

    return 0;
}

int find(int vett[], int SIZE, int elem)
{
    int i;
    int flag = 0;

    for (i = 0; i < SIZE; i++)
        if (vett[i] == elem)
            flag = 1;

    if (flag == 1)
        return 1;
    else
        return 2;
}

Why does Code::Blocks say to me:

|4|error: expected ';', ',' or ')' before numeric constant| 
||In function 'main':| |8|error: expected ']' before ';' token| 
|14|error: 'vett' undeclared (first use in this function)| 
|14|error: (Each undeclared identifier is reported only once| 
|14|error: for each function it appears in.)| 
|14|error: expected ']' before ';' token|
|14|error: expected ')' before ';' token| 
|16|warning: comparison between pointer and integer|

|18|warning: comparison between pointer and integer|
|24|error: expected ';', ',' or ')' before numeric constant|
||=== Build finished: 8 errors, 2 warnings ===|

What did I do wrong?

Answer 1

You are using the preprocessor in places where you shouldn't; let me explain.

Your line

#define SIZE 10

tells the compiler that ALL occurences of the 4 letters "SIZE" are to be replaced by "10".

Which in your code will look like this:

int find(int vet[], int SIZE, int elem); // before preprocessor
int find(int vet[], int 10, int elem);   // after preprocessor -> syntax error

The second line is not valid in C.

What you should do is try to not use your preprocessor definitions as variable names. For instance, what I do is: I name my preprocessor macros with CAPS (which you did) and always name my function variables with only CamelCase or smallletters.

edit: my suggestion:

int find(int vett[], int size, int elem);

int find(int vett[], int size, int elem)
{
    int i;
    int flag = 0;

    for (i = 0; i < size; i++)
        if (vett[i] == elem)
            flag = 1;

    if (flag == 1)
        return 1;
    else
        return 2;
}