I got an error in C while making a quick test program [closed]

Question

I know other versions of this questions exist, but all of the answers for them confuse my beginner brain. All I am trying to do is take a single number as input and then output it, here is the code:

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


int main() {
        int var;

        scanf("%u\n", var);
        printf("%d\n", var);
}

and the error message I got:

warning: format ‘%u’ expects argument of type ‘unsigned int *’, but argument 2 has type ‘int’ [-Wformat=]

The weird thing is that I tried all the format specifiers for integers that I could think of (%d %u %i) and they all returned a similar error.

I'm still a beginner in C so this might be a really stupid question but go easy on me lol

Answer 1

scanf needs to be able to write into var. Currently, you're only passing it a copy of the value of var, but that's of no use to it.

Instead, you need to pass in a pointer to var, so that it can write into that pointer's location:

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


int main() {
    int var;

    scanf("%d", &var);
    printf("%d\n", var);
}