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.



The workspace has defined a Person struct. Inside the main() function, person1 and person2 are initialized as Person types and the names of each have also been set.

Following the initialization and using dot notation:

  • Set the age of person1 to 57
  • Set the age of person2 to 27

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