Array of Objects in C++ with Examples

An array in C/C++ or be it in any programming language is a collection of similar data items stored at contiguous memory locations and elements can be accessed randomly using indices of an array.  They can be used to store the collection of primitive data types such as int, float, double, char, etc of any particular type. To add to it, an array in C/C++ can store derived data types such as structures, pointers, etc. Given below is the picture representation of an array.

Example:
Let's consider an example of taking random integers from the user.

When a class is defined, only the specification for the object is defined; no memory or storage is allocated. To use the data and access functions defined in the class, you need to create objects.

Syntax:

ClassName ObjectName[number of objects];

The Array of Objects stores objects. An array of a class type is also known as an array of objects.

Example#1:
Storing more than one Employee data. Let's assume there is an array of objects for storing employee data emp[50].

👁 Array of objects

Below is the C++ program for storing data of one Employee:

Let's understand the above example -

• In the above example, a class named Employee with id and name is being considered.
• The two functions are declared-
  • getdata(): Taking user input for id and name.
  • putdata(): Showing the data on the console screen.

This program can take the data of only one Employee. What if there is a requirement to add data of more than one Employee. Here comes the answer Array of Objects. An array of objects can be used if there is a need to store data of more than one employee. Below is the C++ program to implement the above approach-

Output:

👁 Image

Explanation:
In this example, more than one Employee's details with an Employee id and name can be stored.

• Employee emp[30] - This is an array of objects having a maximum limit of 30 Employees.
• Two for loops are being used-
  • First one to take the input from user by calling emp[i].getdata() function.
  • Second one to print the data of Employee by calling the function emp[i].putdata() function.

Example#2: 

Output:

👁 Output#2

Advantages of Array of Objects:

1. The array of objects represent storing multiple objects in a single name.
2. In an array of objects, the data can be accessed randomly by using the index number.
3. Reduce the time and memory by storing the data in a single variable.

Disadvantages of Array of Objects:

1. The main disadvantage with arrays of objects is that the constructor runs for each object. If the default constructor doesn't do the right thing for multiple objects in the array, we have to specify the constructor arguments for each element at the time the array is declared, which we wouldn't have to do if we allocated an array of object pointers, and allocated objects as needed.