Xcode struct help

So I am new to programming and even newer to Xcode. I am having trouble using a struct in Xcode. I have gotten to the point where I copied and pasted the code,

struct product {
    int weight;
    float price;
} ;

product apple;

from the c++ site, but when I try to declare the apple's weight via apple.weight = 5; I get errors saying unknown type name 开发者_开发问答'apple' and expected unqualified Id at .

Simple: You have a structure, not a typedef structure.

You can use it as follows:

struct product {
  int weight;
  float price;
};

struct product apple;

void func() {
  apple.weight = 12;
}

However, if you use a typedef, you can give your datatype an actual name:

typedef struct { .. } product;

product apple;

product apple;
apple.weight = 5;

This is valid code inside a function, but not at file scope.

Although at file scope you can initialize it like this:

product apple = { 5 };