C, C++ Structure - The . and the -> notation

 A brief reminder about dot and arrow operators.

The following is an example of the dot operator in a structure;

#include<iostream>

struct Person

{
   char name[30];
   int  age;
}  p;

int main()
{
strcpy(p.name,"John Boy Walton");
p.age =46;
printf("hello, my name is %s and I'm %d years old...\n",p.name,p.age);
}

As we can see from the above, we can't use p.name="whatever" as we would in a class as below for example;

#include <iostream>

using namespace std;

class MyClass
{
private: // Not actually required.
   int privateInt;
public:
   int myNum; // Class variable
   string myString; // Class variable
   int getPrivateInt() // Public GETTER method.

   {
    return privateInt;
   }

   void setPrivateInt(int anInt)// Public SETTER method.
   {
    privateInt=anInt;
   }

   int doubleMe(int anInt)
   {
    return anInt*2;
   }
};

int main()
{
MyClass o;           // Create object of MyClass
o.myNum = 15;   // Assign variable to object.
o.myString = "Some text"; // Assign variable to object.
o.setPrivateInt(665);


// MyClass
cout << o.myNum << endl;
cout << o.myString << endl;
cout << o.getPrivateInt() << endl;
cout << o.doubleMe(50) << endl;
return 0;
}

If p was a pointer to a Person object or an object of type Person then the -> operator would be used instead of the dot.

Using the top section of code as an example;

strcpy(p->name,"John Boy Walton");

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"To access members of a structure, use the dot operator. To access members of a structure through a pointer, use the arrow operator." Source