Lecture Notes: Writing Your First Computer Program

Introduction to the Video

• Host: Caleb from Caleb the Video Maker 2
• Objective: Write the first computer program

Clearing the Shell

• Command: clear
  • Used to clear the terminal screen

Creating a New File

• File Name: hello.c
  • .c denotes a C programming language file

Using Vim Text Editor

• Insert Mode
  • Enter: Press i
  • Exit: Press Esc
• Navigating in Vim
  • Use arrow keys in insert mode
  • More navigation tricks will be covered in future videos

Writing the First Program

Code Structure

• Include Standard IO Library: #include <stdio.h>
• Main Function: int main() { // Code goes here }
• Print Statement: printf("Hello world!\n");
  • \n is a newline character
• Return Statement: return 0;
  • Indicates successful program termination

Saving and Quitting Vim

• Save & Quit: :wq

Compiling and Running the Program

• Compiler: gcc
• Command to Compile: gcc hello.c
  • Success: No output means compilation was successful
  • Error Handling: Compilation errors will be shown if present
• Running the Program: ./a.out
  • Expected Output: Hello world!

Understanding the Program

• Function
  • main() is the entry point of the program
• Output Explanation
  • printf with \n moves cursor to the next line

Handling Errors

• Example of Compilation Error
  • Error messages can help diagnose problems
  • Practice reading error messages

Conclusion

• Preview of next video: More detailed explanation of code components
• Encouragement to persist through errors
• Closing remarks: Like and subscribe for more content