chapter 4 -Structures

Which of the following best describes a structure in C++?

• A group of similar data types stored in a single variable

• A data type used to store characters only

• A user-defined data type that groups variables of different types

• A pointer that stores memory addresses

Answer explanation

A structure (struct) in C++ allows grouping of variables of different data types under a single name. This is useful when representing real-world entities such as a student, which may have name (string), age (int), and grade (char).

What is the key difference between an array and a structure?

• Arrays store values of different types; structures store only one type

• Arrays are user-defined; structures are built-in

• Arrays store values of the same type; structures can store values of different types

• Structures use more memory than arrays

Answer explanation

Arrays in C++ are used to store multiple values of the same data type, whereas structures can combine values of different data types (e.g., int, char, string) under one name.

Which syntax correctly declares a structure in C++?

• structure Student { string name; int age; };

• struct Student = { string name; int age; };

• struct Student { string name; int age; };

• Student structure { string name; int age; };

Answer explanation

The correct keyword to declare a structure is struct, followed by the structure name and a block containing the members.

How do you access a member of a structure variable named student1 with a member name?

• student1->name;

• student1:name;

• student1.name;

• student1->name();

Answer explanation

When using a structure variable (not a pointer), use the dot operator . to access its members. The arrow operator -> is used only with structure pointers.

What happens when you define a structure but do not create a variable of it?

• The program will run with warnings

• The compiler ignores the structure

• It reserves memory for the structure

• No memory is allocated until a structure variable is created

Answer explanation

Defining a structure only creates a new data type. Memory is only allocated when you declare variables of that structure type.