DCS1101 - Week 12 (Structures)

Learning Contents

• Introduction to structures

• Structure syntaxes

• The application of syntaxes

Multiple Choice

A structure in C++ is best described as:

• A predefined class that cannot be modified.
• A built-in data type that only holds integers.
• A collection of functions that perform operations.
• A user-defined data type that groups variables of different types.

Multiple Choice

Which keyword is used to declare a structure?

• define
• class
• object
• struct

Multiple Choice

A structure can contain:

• Only integers

• Only floating numbers

• Any combination of data types

• Only characters

Multiple Choice

What is the output of the following code?

struct Box { int w; int h; };

int main() {

Box b = {5, 8};

cout << b.w + b.h;

}

• 10
• 12
• 13
• 15

Multiple Choice

What is the error of the following?

struct Person {

int age;

string name;

};

int main() {

cout << Person.age;

}

• Can access member 'age' directly from struct type 'Person'.
• The struct definition is missing a constructor for 'Person'.
• The 'cout' statement is incorrectly formatted with '<<' operator.
• Cannot access member 'age' directly from struct type 'Person'; need an instance.

Multiple Choice

What is the output of this?

struct Num { int n; };

int main() {

Num x = {7};

Num y = x;

y.n = 20;

cout << x.n;

}

• 7
• 10
• 20
• 7.0

Multiple Choice

What is the error of this code?

struct Item {

string name;

float price;

};

Item item("Soda", 2.5);

• The struct 'Item' lacks a constructor for initialization.
• The struct 'Item' is missing a destructor.
• The 'price' field should be an integer type.
• The 'name' field should be declared as a char array.

Previous Topic	Relation to Structures
Variables	Structures contain multiple variable types.
Arrays	Structures allow arrays as members, and arrays of structures.
Functions	Structures can be passed to functions by value or reference.
Loops	Often used to process structure arrays (for, while).
Selection (if/switch)	To compare structure members (e.g., highest price).
File Processing	Structures store data that can later be written to files.

Real Programming Uses

• To group different info about one item (student, car, book).

• To create arrays of objects easily.

• To pass related data into functions without many parameters.

• To create more complex data types before learning classes/objects.

Real Programming Uses

• Games (player stats)

• Finance apps (transaction records)

• University systems (student database)

• Inventory systems (products)

• File handling records

The first inventory systen

Material Requirements Planning (MRP) – Late 1960s

• Developed by IBM and large manufacturing companies.

• Used on early mainframe computers.

• Helped factories track inventory, production schedules, and materials needed.

• Companies like Black & Decker were among the first major adopters (1964).

Timeline for MRP

Year	System	Notes
Pre-1960s	Manual, paper forms	No software; physical cards & ledgers.
1960s	MRP (Material Requirements Planning)	First computerized inventory system on mainframes.
1970s	MRP II (Manufacturing Resource Planning)	Added scheduling, capacity planning.
1990s	ERP (Enterprise Resource Planning)	Integrated inventory with HR, finance, logistics (SAP, Oracle).
2000s–Today	Cloud-based inventory tools	QuickBooks, Zoho Inventory, Odoo, etc.

Open Ended

Imagine your college needs a system to keep track of student attendance.

How could structures and functions be used together to simplify the program design?

Thank you!