C++ Lecture 10 - Structures

Structured Programming in C++ (Lecture 10 - Structures)

• Structures in C++ are user-defined data types
• Structures group different variable types under a single name
• Structures help organize complex data efficiently.
• A structure member is a variable within a structure
• Structures can contain various data types (int, string, bool, float, etc.)

Objectives

• Defining what are structures in C++
• Understanding the purpose of using structures in C++ programs
• Learning the syntax and declaration of structures
• Exploring how to access and use structure members
• Differentiating between structures and classes
• Understanding practical applications of structures (e.g., databases, graphics programming)

What are Structures?

• Structures are used to group related data items together
• Structures are efficient for organizing data
• Structures are a fundamental concept for understanding classes.
• Structures can be used in real-world applications in databases, file systems, and networking.

Why Use Structures in C++?

• Data Organization: Combining related data types into a single unit.
• Code Clarity: Simplifying complex data manipulation by grouping related data.
• Reuse: A single structure can be reused in various parts of a program.
• Flexibility: It can include arrays, pointers, and other structures.

Creating a Structure

• Use the struct keyword to define a structure.
• Declare members (variables) inside curly braces.
• Specify the structure variable name after the declaration.

Syntax and Declaration

• The struct keyword introduces the structure definition.
• Structure members are declared within curly braces.
• Members can have different data types.
• Structures are defined outside of the main function.

Accessing and Using Structures

• Use the dot operator (.) to access members of a structure variable
• Structure members can be assigned values after declaration.
• Data can be initialized at declaration

Structures vs. Classes

• Structure members are public by default in older C++ versions
• Class members are private by default.
• Structures are simpler for grouping data, whereas classes enhance code organization by allowing methods and behaviors.

Practical Applications

• Database Records: Storing student details or catalog information.
• Graphics Programming: Storing coordinates, colors, and shapes.
• File Handling: Grouping related file data for reading and writing.
• Network Protocols: Defining message formats with structured data.

Nested Structures

• Structures within structures.
• Used for hierarchical data organization.

Multi Structure Variables Definition

• Creating multiple structure variables of the same type.
• Using a comma to define multiple instances of the structure after its definition.

One Structure in Multiple Variables

• Can use commas to declare multiple variables of the same structure definition
• Enables creating multiple instances of a structure at once.

Example: Student Management

• Demonstrates usage of the structure to represent student data (name, roll number, marks)
• Shows how to initialize and access structure members
• Output displayed shows the members of the structure

Example: Employee Record

• Demonstrates a structure example containing employee data such as name, ID, position, and salary.
• Emphasizes accessing structure members from within a program.

Example: Geometry - Points and Rectangles

• Demonstration of structure usage to representing coordinates of a rectangle by using two points

Managing a Team of Players

• Illustrates usage of arrays containing structured data
• Used to display player details such as name, age and score

Library System with Arrays and Nested Structures

.Demonstrates creating complex data structures

• Shows how to define structures for publishers and books.
• Show code example with outputs demonstrating nested structure examples and access using arrays

Conclusion

• Structures effectively group variables into a single unit
• Structure data is lightweight facilitating efficient organization.
• Structures serve as foundation for more advanced concepts like classes
• Structures are practical for real-world applications like databases, file systems, and networking