Introduction to Computer Programming

• A computer program is a sequence of instructions written in a computer programming language.
• Computer programs are also called computer software--they can range in length from a few lines to millions of lines of instruction.
• Instructions in computer programs are also called program source code.
• Computer programming is also known as program coding.

What is Computer Programming?

• Computer programming refers to the process of designing and writing computer programs.
• A programming language is a computer language used by programmers to communicate with computers.
• These are a set of instructions written in a language understood by the computer, such as C, C++, Java, or Python, to perform a specific task.

Software Applications

• System software includes compilers, editors, and file management utilities.
• Application software includes stand-alone programs designed for specific needs.
• Engineering/scientific software is characterized by number-crunching algorithms for tasks like automotive stress analysis, molecular biology, and orbital dynamics.
• Embedded software resides within a product or system, like keypad control for a microwave oven or a car's dashboard display.
• Product-line software caters to a limited marketplace, such as word processing, graphics, and database management.
• WebApps (Web applications) are network-centric software, supported by more sophisticated computing environments that integrates with remote databases and business applications as Web 2.0 emerges.
• AI software uses non-numerical algorithms to solve complex problems, such as those found in robotics, expert systems, pattern recognition, and game playing.

System Software

• Maintains system resources and provides a path for application software.
• Low-level languages write system software.
• It is general-purpose software designed to control, integrate, and manage hardware components and application software.
• System software runs independently.
• System software programming is more complex than application software programming.
• Operating systems are examples of system software.

Application Software

• Built for specific tasks.
• High-level languages are used to write application software.
• Specific-purpose software are sets of computer programs installed to perform specific tasks.
• Application software relies on system software because it needs a platform to function.
• Application software programming is simpler compared to system software programming.
• Photoshop and VLC media player are examples of application software.

Basic Fundamental Programming Concepts

• Basic programming concepts are similar across languages.
• These programming concepts include variable declaration, basic syntax, data types and structures, flow control structures, functional programming, object-oriented programming, debugging, IDEs, and coding environments.

Variable Declaration

• Variables are containers for storing data values; it's a memory location of data.
• Variables are created using declaration or keywords.
• Variable names are generally alphanumeric; they can contain special characters.
• Variable names can use a-z, 0-9, and special characters such as the $_$ (underscore) or the $ (dollar sign)
• Variables hold values of any data type supported by the programming language, and this value may change during program execution.

Basic Syntax

• Every programming language has its syntax.
• Syntax refers to the set of rules that determine language structure.
• Programming languages cannot be read or understood without following syntax.

Data Type & Structures

• Data types are the classifications of data.
• Common data types include strings, booleans (true or false), numbers (integers and floating-point), characters, and arrays.
• Data structures are collections of data values with operations.
• Common data structures include stacks, heaps, trees, linked lists, queues, arrays, tables, and graphs.

Flow Control Structures

• Control structures are fundamental components of computer programs allowing a program to "decide" direction.
• Three basic types of control structures: sequential, selection, and iteration.

Sequential

• Basic control flow involving the execution of code statements one after the other.
• Following a cooking recipe is a real-world example of sequential control flow.

Selection (Conditionals)

• The computer decides what action to perform based on the result of a test or condition equaling true or false.

Iteration (Loops)

• Loops are programming structures that allow a statement or block of code to be run repeatedly until a specified condition is no longer true (Boolean, true or false).
• Loops are one of the most powerful and fundamental programming concepts.

Functional Programming

• Functions are containers that take in a set of inputs and return an output which is not required for functions to return a value.
• Pure functions will always give the same result for the same set of inputs.
• Functional programming builds software using only pure functions, which eliminates data mutation or side effects.

Object-Oriented Programming

• Object-Oriented Programming (OOP) revolves around 'objects' and 'methods'.
• There are four principles of OOP: inheritance, polymorphism, abstraction, and encapsulation.

Debugging

• Detects/removes existing or potential errors, defects, or 'loopholes' in code.

IDEs and Coding Environments

• Integrated Development Environment (IDE) applications are used to write code and organize text groups, which increase efficiency and productivity.
• Code completion, code compilation, debugging and syntax, highlighting are features in IDEs.
• Examples of IDE's: Visual Studio Code, IntelliJ IDEA, NetBeans and Eclipse.

What is an Algorithm?

• An algorithm is a set of commands that must be followed for a computer to perform calculations or other problem-solving operations.
• According to its formal definition, an algorithm is a finite set of instructions carried out in a specific order to perform a particular task.
• Algorithms are not the entire program or code; it is simple logic to a problem represented as an informal description in the form of a flowchart or pseudocode.

Characteristics of an Algorithm

• Well-defined inputs are required; they can be given a value other than 0.
• Well-defined outputs ensure one or more outcomes at the end.
• Must be Unambiguous to be clear and straightforward.
• Finiteness requires an algorithm to have a limited and countable number of instructions.
• Effective algorithms affect the overall process and should be adequate.
• Language independence allows instructions to be implemented in any language, producing the same results.

Example Problems for Algorithms

• Problem: Create an algorithm that multiplies two numbers and displays the output.
• Method 1: Declares three integers, defines values, multiplies them, stores result to z, print z, and stop.
• Method 2: Get values of x & y, z = x * y, display z, and stop.
• The second method is used in algorithm design because it lets the analyst ignore unwanted definitions easily, and shows which operations are being used and how the process progresses.
• Writing step numbers is optional.