I have the following code:
include <stdlib.h>
typedef struct foo{
int x;
}Foo;
void funcY(Foo *f1)
{
printf("%d", f1.x);
}
void funcX(Foo *f1)
{
printf("%d", f1.x);
funcY(f1); <---- is this correct?
}
int main()
{
Foo *foo1 = (struct foo *)malloc(sizeof(struct foo));
foo1.x = 10;
funcX(foo1);
return 0;
}
I don't know exactly how to label this problem. What is the best way for me to approach this?
funcY(f1); <---- is this correct?
Yes, this particular line is correct. However, several other parts that aren't: specifically, accessing struct members by pointer needs -> operator, rather than a dot:
printf("%d", f1->x);
Another small issue is that one should not cast malloc in C:
Foo *foo1 = malloc(sizeof(struct foo));
Finally, you are missing a call to free(foo) to deallocate malloc-ed memory. Note that you do not have to use malloc - allocate the struct in the automatic store, and use & to access its address:
int main()
{
Foo foo1;
foo1.x = 10;
funcX(&foo1);
return 0;
}
funcY(f1) is correct - it passes the Foo pointer to funcY, and since funcY accepts a Foo pointer we can assume it'll work as intended.
printf("%d", f1.x);, however, is not correct. f1 is a Foo pointer, not a Foo. To access it's x field you need to derefer it first - (*f1).x - or use the sytactic sugar f1->x.
