Now that we’ve leveraged that power of structures to package variables together we can discuss how we can access each member variable individually using dot notation.

Dot notation is a C operator that allows you to access and modify a member variable of a structure.

struct Bottle {
  char* name;
  int maxCapacity;
  int currentCapacity;
};

struct Bottle myBottle = {"Medium Bottle", 24, 0};

// Fill some of myBottle
myBottle.currentCapacity = 10;
printf("The bottle is now filled to %d", myBottle.currentCapacity);

In the example above:

• A bottle structure is defined and initialized with the variable myBottle
• The member variable currentCapacity is accessed and set to 10 with myBottle.currentCapacity = 10
• The same variable is accessed again using the dot operator and output with printf()

You can also use the dot operator to initialize a structure if you’d like to declare it first without initializing it right away like:

struct Bottle myBottle;
myBottle.name = "Medium Bottle";
myBottle.maxCapacity = 24;
myBottle.currentCapacity = 0;

The dot operator is essential in enhancing the packaging benefits of structs by allowing you to access any of the Bottle member variables through the variable myBottle.