EEE21501 Principles of Programming

Study Notes

Programming languages and software systems are evolving to achieve higher levels of abstraction.
- Hiding details of hardware and platform interfaces.
- Reducing development time.
- Reducing costs of development and maintenance.
- Increasing portability.
- Relying on libraries for commonly performed tasks.
Abstraction can be applied to control or data.
- Data abstraction manages data items in a meaningful manner (data types).
- Control abstractions manage the order of execution within a program.

Problem solving refers to the entire process of taking a problem statement and developing a computer program to solve it.
The solution passes through many phases:
- Problem definition.
- Maintenance.
- Design.
- Coding/Implementation.
- Deployment.
- Testing.

An algorithm is a step-by-step specification of a method to solve a problem in a finite amount of time.
Algorithms operate on a collection of data, performing actions like adding, manipulating, and removing data.

Good solutions need to consider tangible costs.
Costs include factors like:
- Computer resources: memory and CPU time.
- Development, maintenance, and expansion costs.

Modularity breaks a solution into modules.
Abstraction clearly specifies each module before programming.
Changes to one part of a modular solution don't affect other parts.
Data abstraction focuses on the function of operations, not how they are implemented.

Encapsulation packages information to hide unnecessary details while making the intended elements visible.
Modular solutions can be achieved by identifying components called objects that combine data and operations on the data.

Key principles of object-oriented programming:
- Encapsulation: Objects combine data and operations.
- Inheritance: Classes can inherit properties from other classes.
- Polymorphism: Objects can determine appropriate operations at execution time.

An ADT is a collection of data and a set of operations for manipulating that data.
ADTs support abstraction, encapsulation, and information hiding, focusing equally on data and operations.
ADTs are implemented using data structures.
Built-in ADTs: Boolean, integer, real, array.
User-defined ADTs: list, stack, queue, tree, linked list.

Data structures determine how data is organized in memory, affecting the efficiency of different operations.
The choice of data structures depends on which operation the application uses most frequently.