Programming Fundamentals and OOP Cheat Sheet

MEGA CHEAT SHEET

1. Programming Fundamentals

Software Development Life Cycle (SDLC)

Steps: Requirements → Specifications → Design → Development → Integration → Testing/Debugging → Installation → Maintenance.

Mnemonic: Really Smart Developers In Tech Install Machines.

Algorithms

• Control Structures:
  • Sequence (In Order)
  • Selection (If/Else)
  • Iteration (Loops)
• Design Strategies: Divide and Conquer, Backtracking.
• Representations: Pseudocode, Flowcharts, Structure Charts, Abstraction Diagrams.
• Checking: Identify Input/Output, Purpose, Desk Check with data.

Programming Paradigms

• Imperative: Step-by-step instructions (e.g., Python).
• OOP: Objects and classes (e.g., Java, Python).
• Logic: Facts and rules (e.g., Prolog).
• Functional: Pure functions, no state (e.g., Haskell).

Data Representation

• Number Systems: Binary (Base 2), Decimal (Base 10), Hexadecimal (Base 16).
• Two's Complement: Represents negative numbers.
• Data Types: Char, String, Boolean, Real/Float, Integer, Date/Time.

Data Structures

• Arrays (1D/2D), Lists, Trees, Stacks, Hash Tables, Records, Sequential Files.

Debugging Techniques

• Tools: Breakpoints, Step-through, Watches, Debug Output.
• Errors:
  • Syntax (Grammar mistake).
  • Logic (Wrong algorithm).
  • Runtime (Crash at execution).

Software Testing

• Test Data: Boundary values, Path coverage, Faulty/Abnormal data.
• Models: Waterfall (Rigid, Structured) vs. Agile (Flexible, Iterative).

2. Object-Oriented Paradigm (20 Marks)

Key OOP Principles

• Objects: Instances of classes.
• Classes: Blueprints for objects.
• Encapsulation: Hide internal data, expose only methods.
• Abstraction: Show essential details only.
• Inheritance: Child inherits from parent.
• Generalization: Common traits grouped into a superclass.
• Polymorphism: Same method, different behavior across classes.

Procedural vs. OOP

• Procedural: Function-based, linear (e.g., C).
• OOP: Object-based, modular, reusable (e.g., Python, Java).

Design Tools

• Diagrams:
  • Data Flow Diagram (DFD): Shows data movement.
  • Structure Chart: Module breakdown.
  • Class Diagram: Attributes, methods, and relationships.

Code Practices

• Clean mainline code.
• One logical task per subroutine.
• Use stubs for incomplete methods.
• Version control and commenting.

Testing Methodologies

• Unit: Single component.
• Subsystem: Module level.
• System: Full program.
• Black Box: External inputs/outputs.
• White Box: Internal logic.
• Grey Box: Mix of both.