How to pass a structure to a function in C++

How to pass a structure to a function in C++

In C++, a structure (or struct) is a user-defined data type that allows you to combine data items of different kinds. You can create a structure to group related variables together. When you want to use a structure in a function, you can pass it as a parameter. This allows the function to access and manipulate the structure's data.

Defining a Structure

To define a structure, you use the struct keyword followed by the structure name and its members. Here is an example:

struct Person {  int age;  float height;  char name[50];};

In this example, we have defined a structure called Person that contains three members: age (an integer), height (a float), and name (an array of characters).

Passing a Structure to a Function

To pass a structure to a function, you can use either pass by value or pass by reference. Each method has its own use cases.

Pass by Value

When you pass a structure by value, a copy of the structure is made. Changes made to the copy do not affect the original structure. Here is how to do it:

void displayPerson(Person p) {  cout << "Name: " << p.name << endl;  cout << "Age: " << p.age << endl;  cout << "Height: " << p.height << endl;} 

In this function, displayPerson, we take a Person structure as a parameter. We can then access its members and display them. To call this function, you would do the following:

Person person1;  strcpy(person1.name, "John");  person1.age = 30;  person1.height = 1.75;  displayPerson(person1);

In this example, we create a Person object called person1, set its members, and then pass it to the displayPerson function.

Pass by Reference

Passing a structure by reference allows the function to modify the original structure. You do this by using the & symbol in the function parameter. Here is an example:

void updatePerson(Person &p) {  p.age += 1;  strcpy(p.name, "Updated Name");}

In this function, updatePerson, we take a reference to a Person structure. This means that any changes made to p will affect the original structure.

To call this function, you would do the following:

updatePerson(person1);

After calling updatePerson, the age of person1 will be increased by 1, and the name will be changed to