Introduction to Programming Lecture Notes

Overview

• Instructors: Steven and Shawn
• Duration: 90 minutes
• Content: 21 segments covering the basics of computer programming applicable to various languages.
• Topics Covered:
  • What is programming?
  • Loops and arrays
  • Reading and writing code
  • Debugging code
  • Planning strategies

What is Programming?

• Definition: Preparing instructional programs for devices; simplified as getting a computer to perform tasks without mistakes.
• Analogy: Giving instructions to a less competent friend (comparing programming to telling a friend how to build something).
• Key Concept: Computers only understand machine code (binary - ones and zeros), so programmers translate instructions to a language the computer understands.

Programming Languages

• Role: Act as middlemen to translate human-friendly code into machine code.
• Types:
  • General Purpose Languages: Python, Java.
  • Specific Purpose Languages: C, HTML, CSS.
• Power Measurement: Low-level languages (near machine code) vs. high-level languages (more abstract).

Writing Code

• IDEs (Integrated Development Environment): Provide a graphical interface to aid in writing, running, and debugging code. Features include:
  • Built-in error checking
  • Auto-fill functions
  • Project organization
• SYNTAX:
  • Each programming language has specific rules (grammar) that must be followed (e.g., semicolons in Java).
  • Syntax errors often lead to program failures.

Console Usage

• Purpose: Output messages and debug statements.
• Print Statement: Fundamental for displaying results. Syntax varies between languages but is essential for interaction with the programmer.

Basic Mathematics in Programming

• Key Arithmetic Operations: Addition, subtraction, multiplication, division, modulus.
• Strings: Text data type, how to handle them through concatenation.

Variables

• Definition: Store information (like a box with a label).
• Types: Integers, Booleans, Floats, Strings, Characters.
• Importance: Essential for referencing, modifying, and storing data within programs.

Conditional Statements

• Structure: if, else if, else - execute code depending on boolean conditions.
• Flow Control: Allows programs to execute code paths based on input variables.

Arrays

• Definition: Collection of items (like a list) stored together.
• Types: One-dimensional and multi-dimensional arrays (e.g., 2D arrays).
• Key Points:
  • Use indices to refer to elements (starting at 0).
  • Fixed size upon creation.

Loops

• Purpose: Run code repeatedly.
• Types:
  • For Loop: Fixed number of iterations.
  • For Each Loop: Iterates over each element in an array.
  • While Loop: Continues running as long as a condition is true.
• Important Note: Avoid infinite loops that can crash programs.

Error Types

• Syntax Errors: Easy to correct; occur when the code violates language rules.
• Runtime Errors: Occur during execution; common causes include infinite loops or dividing by zero.
• Logic Errors: Program runs but produces incorrect results; the hardest to debug.

Debugging Strategies

• Common Techniques: Using print statements to track variable states and program flow; breakpoints for pausing execution.
• Commenting Out Code: Useful for testing sections of code without deleting.

Functions

• Definition: Reusable code segments, allow easy execution of operations.
• Types:
  • With or without arguments.
  • With or without return values.
• Importance: Abstract code, reduce redundancy, make changes easily manageable.

Importing Libraries

• Purpose: Use pre-written functions without writing them from scratch.
• Structure: Use an import statement to access libraries and packages containing functions.

Recursion

• Definition: Functions that call themselves, useful for breaking problems into smaller parts.
• Key Concept: Must have a base case to prevent infinite recursion.

Pseudocode and Planning

• Importance: Plan out code to identify potential problems before coding begins.
• Techniques:
  • Flowcharts: Visual representation of functions.
  • Step-by-step descriptions: Write down algorithmic logic before coding.
  • Feature lists: Outline functionalities needed for applications.

Choosing a Programming Language

• Considerations: Type of project (web development, app development), language strengths (general purpose, scripting languages).
• Popular Languages: Java, Python, C++, HTML, CSS.

Next Steps for Learning Programming

• Research: Find resources specific to the programming language of interest.
• Practice: Explore coding challenges on websites like CodingBat, Coderbyte, or HackerRank.
• Classes: Consider taking formal classes in programming or computer science.

Conclusion

• Encouragement: Explore coding, contribute to projects on GitHub, learn continuously.
• Community: Join computer science communities online for support and development.

---