C++ Data Types

A structure in C++ is a user-defined data type that allows the programmer to represent a collection of logically related data items, which may be of different types, under a common name. An example of a structure in C++ is:

struct student { 
    int adm_no; 
    char name; 
    char group; 
    float fee; 
}

If values are not provided for all the elements of a structure during initialization, the given values will be assigned to the elements on a First Come First Served (FCFS) basis. The remaining elements will be assigned with 0 (zero) or '\0' (null character) depending on numeric or string.

A C++ statement to initialize the student structure provided in the text is:

student S={101, "Amith", "Computer Science", 20000}

The purpose of the data types specified within the pair of braces when declaring variables of a structure is to determine the size of the structure. These data types may be basic data types or user-defined data types.

The size of the structure 'student' in C++ is determined by the sum of the sizes of its individual elements. In this specific example, the size of the structure will be $4 + 20 \times 1 + 10 \times 1 + 4 = 38$ bytes.