C++ Structures (struct)

Structures (also called structs) are a way to group several related variables into one place. Each variable in the structure is known as a member of the structure.

Unlike an array, a structure can contain many different data types (int, string, bool, etc.).

Create a Structure

To create a structure, use the struct keyword and declare each of its members inside curly braces.

After the declaration, specify the name of the structure variable (myStructure in the example below):

struct < // Structure declaration
int myNum; // Member (int variable)
string myString; // Member (string variable)
> myStructure; // Structure variable

Access Structure Members

To access members of a structure, use the dot syntax ( . ):

Example

Assign data to members of a structure and print it:

// Create a structure variable called myStructure
struct int myNum;
string myString;
> myStructure;

// Assign values to members of myStructure
myStructure.myNum = 1;
myStructure.myString = "Hello World!";

One Structure in Multiple Variables

You can use a comma ( , ) to use one structure in many variables:

struct <
int myNum;
string myString;
> myStruct1, myStruct2, myStruct3; // Multiple structure variables separated with commas

This example shows how to use a structure in two different variables:

Example

Use one structure to represent two cars:

struct <
string brand;
string model;
int year;
> myCar1, myCar2; // We can add variables by separating them with a comma here

// Put data into the first structure
myCar1.brand = "BMW";
myCar1.model = "X5";
myCar1.year = 1999;

// Put data into the second structure
myCar2.brand = "Ford";
myCar2.model = "Mustang";
myCar2.year = 1969;

Named Structures

By giving a name to the structure, you can treat it as a data type. This means that you can create variables with this structure anywhere in the program at any time.

To create a named structure, put the name of the structure right after the struct keyword:

To declare a variable that uses the structure, use the name of the structure as the data type of the variable:

Example

Use one structure to represent two cars:

// Declare a structure named "car"
struct car string brand;
string model;
int year;
>;

int main() // Create a car structure and store it in myCar1;
car myCar1;
myCar1.brand = "BMW";
myCar1.model = "X5";
myCar1.year = 1999;

// Create another car structure and store it in myCar2;
car myCar2;
myCar2.brand = "Ford";
myCar2.model = "Mustang";
myCar2.year = 1969;