CCS 1400: Introduction to Programming and Flowcharting

Course Objectives

Define Programming: Establish a foundational understanding of the programming process.
Familiarize with Programming Universals: Understand the core elements shared across various programming languages.
Identify Flowchart Symbols: Recognize the standard graphical representations used in process mapping.
Create a Flowchart: Apply logic to design a visual representation of a program or process.

The Task of Programming

Programming Definition: The process of preparing an instructional program for a device, such as a computer.
Program Definition: A specific set of instructions that assists a computer in performing various tasks.
Learning Requirements: Mastering a computer programming language involves learning two critical components:
- Vocabulary: The specific set of words or commands used by the language.
- Syntax: The specific rules of any given language that govern how commands are written and structured.
Types of Programming Errors:
- Syntax errors: Violations of the language's rule set (e.g., typos, missing punctuation).
- Run-time errors: Errors that occur while the program is executing (e.g., dividing by zero).
- Logical errors: Flaws in the program's logic that lead to incorrect results even if the code runs without crashing.

Programming Universals and Language Classifications

Programming Language: A tool used to write a program or a set of instructions for a computer.
Primary Classifications:
- Machine Level Language:
  - The lowest level of programming language.
  - Directly handles binary data ( $0$ s and $1$ s).
  - Interacts directly with the system hardware.
  - Characteristics: Not portable and not readable by humans.
- Assembly Level Language:
  - A low-level language that consists of specific instruction formats called commands.
  - Uses symbols to represent fields of instructions.
  - Operates very close to machine level language.
  - Requires an Assembler to translate the assembly level program into machine level (binary) code.
  - Characteristics: In human-readable format; takes less time to write and debug than machine code.
  - Comparison Example:
    - Assembly Language: SUB AX, BX | Machine Code: 0010101110000011
    - Assembly Language: MOV CX, AX | Machine Code: 100010111001000
    - Assembly Language: MOV DX, 0 | Machine Code: 10111010000000000000000
- High-level Language:
  - Uses a format or syntax that is most familiar to human users.
  - Instructions in this language are specifically referred to as codes or scripts.
  - Requires a Compiler or Interpreter to convert the code into machine level language.
  - Examples: C++, Python, Java.
  - Characteristics: Easy to write, less time-consuming, and highly readable.
  - Code Example: c if (age < 18) { printf("You are not eligible to vote"); } else { printf("You are eligible to vote"); }

Translation and Execution Tools

Interpreter: A program that translates programming language instructions sequentially, one line at a time.
Compiler: A program that translates the entire program into machine code all at once before execution.
Running a Program: The act of issuing a command to execute the program statements written in the code.
Testing a Program: Using sample data to determine if the program produces the correct results.

Logic and Control Structures

Control Structures: The logic components within a program that determine the flow of execution.
Sequence Structure: Steps are executed one after another in a linear fashion without interruption.
Selection Structure: Used to perform different tasks based on whether a specific condition is met (often referred to as decision making).
Loop Structure: Repeatedly performs a set of actions as long as a specified condition remains unchanged.

Procedural Programming

Concepts:
- Programs consist of a series of steps or procedures that take place consecutively.
- Based on the concept of "calling procedures."
- Procedures: Also referred to as routines, subroutines, or functions. These consist of a series of computational steps to be executed.
Functionality: During program execution, any specific procedure can be called by other procedures or even by itself.
Language Examples:
- COBOL
- BASIC
- ALGOL
- FORTRAN
- Pascal
- C
Code Implementation Example (C Language): c #include <stdio.h> // Function to calculate area of a circle double calculate_area(double radius) { double area = 3.14159 * radius * radius; return area; } int main() { double radius = 7.0; double area = calculate_area(radius); printf("The area of the circle with radius %.2f is %.2f\n", radius, area); return 0; }     
- Logic calculation: Area = $3.14159 \times \text{radius} \times \text{radius}$ .
- Sample Output: "The area of the circle with radius 7.00 is 153.94"

Software Development Methodology

Software Development Overview: The process of creating, testing, and maintaining software products and services to meet user needs.
Development Methodologies: Frameworks or models that guide the process, outlining activities, deliverables, and the roles and responsibilities of the team members.
Phases of the Software Development Life Cycle (SDLC):
1. Project planning
2. Gathering requirements and analysis
3. Design
4. Coding or implementation
5. Testing
6. Deployment
7. Maintenance
Common SDLC Models:
- Waterfall Model: A linear, sequential approach through requirements, design, implementation, testing, deployment, and maintenance.
- Agile Methodology: An iterative approach focusing on brainstorming, design, development, testing, and deployment with constant feedback loops and demos.
- Spiral Model: A risk-driven model involving objective identification, evaluations, risk management, development, and planning for the next phase.

Flowcharting: Symbols and Representation

Definition: A flowchart is a graphical representation of the sequence of steps in a process.
Standard Flowchart Symbols:
- Start/End (Oval): Used at the beginning and the end of the algorithm to signify the program's bounds.
- Arrows: Show the relationship and flow direction between different shapes.
- Input/Output (Parallelogram): Used for denoting program data entry (Input) and data display (Output).
- Process (Rectangle): Indicates internal processes such as mathematical operations or data assignments.
- Decision (Diamond): Represents decision points where an answer is typically "Yes" or "No." Lines representing different branches emerge from different points of the diamond.
- On-page Connector (Small Circle): Connects different parts of a flowchart that reside on the same page, usually marked with a letter to show matching points.
- Off-page Connector (Pentagon-like Shape): Connects parts of a flowchart that are spread across different pages.

Flowchart Logic Examples

Sum of Two Integers Algorithm:
1. Enter a number
2. Enter another number
3. Get the sum of the two numbers
4. Print the sum
Sum Flowchart Structure:
- Start -> Read A -> Read B -> Sum = $A + B$ -> Print Sum -> End
Average Calculation Flowchart:
- Start -> Take num1, num2 -> Average = $\frac{\text{num1} + \text{num2}}{2}$ -> Print Average -> End

Integrated Development Environment (IDE)

IDE Definition: A coding tool that assists in automating editing, compiling, testing, and other SDLC steps.
Purpose: Simplifies the process of writing, executing, and debugging code. It includes multiple tools used for the creation and testing of software.
Popular Python IDEs:
- Wing
- Atom
- Eric
- PyDev
- PyCharm
- Spyder
- Microsoft Visual Studio
- Jupyter Notebook
- Thonny
- Rodeo