IT2402 Basics of Programming

Programming Basics

• A computer program consists of a sequential set of instructions (codes) written in a programming language for the computer to perform specific tasks.
• Examples of software include system software, web browsers, utility software, multimedia software, and spreadsheet software.
• Programs are executed sequentially unless specified otherwise, conveying tasks that a programming language supports.
• A programming language is defined by grammatical rules that instruct a computer to perform functions or behaviors.

The Art and Science of Programming

• Programming involves creating codes that instruct computers on problem-solving and task execution.
• Skills in programming lead to diverse careers such as software development, web development, data science, and artificial intelligence.
• Developing programming skills enhances critical thinking, logical reasoning, and problem-solving abilities by breaking down complex tasks into smaller steps.

Evolution and History of Programming

• Initial programming was done using low-level machine code (binary).
• The advent of high-level programming languages simplified the coding process, making it easier to write human-readable syntax.
• Modern programming encompasses a wide range of languages and tools tailored to various programming paradigms and application needs.

Programming Paradigms

• A programming paradigm is a pattern for structuring and organizing code, providing a conceptual framework for problem-solving.
• Selection of a programming language depends on project requirements, performance, community support, and available libraries or frameworks.

Key Programming Terminologies

• Syntax: Rules defining valid combinations of symbols in a programming language.
• Command: Unique instructions given to a computer to perform tasks (e.g., “print”).
• Integrated Development Environment (IDE): Software for coding, checking syntax, and running code; may support multiple languages or be language-specific.
• Library: A collection of resources, such as functions and objects, usable individually but needing configuration to work together.
• Interpreter: A program executing high-level language instructions directly without conversion to machine language.
• Assembler: Converts assembly code into machine language.
• Compiler: Converts high-level language code into machine-readable format.

Algorithm, Pseudocode, and Flowchart

• An algorithm is a step-by-step set of operations leading to a solution for a problem and should be written in clear, understandable language.
• Example: To calculate the volume of a rectangle, input length, width, and height, and use the formula: volume = length × width × height.
• The problem-solving process includes problem analysis, algorithm design, coding, and execution.

Pseudocode

• A pseudocode is a simplified notation used to outline an algorithm's steps, making it easier for those with basic programming knowledge to follow.
• Common symbols in pseudocode include arithmetic operations, comparisons, assignment, and logical commands.

Flowchart

• A flowchart visually represents the steps of an algorithm using standard symbols to describe processes and decisions.
• Two categories of flowcharts: Program flowcharts (focus on software logic) and System flowcharts (show system interactions and data flow).

Flowchart Symbols

• Terminal: Represents start and end points.
• Input/Output: Indicates input or output operations.
• Computer Processing: Denotes processing actions.
• Decision: Shows where a decision is required to proceed.

Rules for Creating Flowcharts

• Use only standard symbols and show flow from top to bottom and/or left to right.
• Each symbol must have a single entry and exit point, except for decision symbols.
• Expression within symbols should be language-independent and decision branches should be clearly labeled.