Lesson 1: C++ toolchain and basics: Concept walkthrough

Concept Explanation

This lesson helps you get comfortable with the smallest complete C++ program: include a header, define `main`, print output, and return a value. The goal is not speed or cleverness yet. The goal is to recognize the structure of a program that compiles cleanly and runs exactly as expected. By the end, you should be able to open a file, write a tiny C++ program by hand, build it, run it, and explain what each line is doing.

Where to Put the Code

1. Start with variables and inputs. Keep includes, main function, and data types explicit.
2. Add processing logic in the middle section.
3. Finish with output and quick validation.

Command Reference

• Compile the file, run it, and confirm that both output lines appear in the terminal.
• Point to each required part of the program: `#include`, `main`, output statement, and `return 0;`.
• Change one message, rebuild, and verify that the executable reflects your edit.
• Keep the first example small enough that you can retype it from memory without copying.

Step-by-step Guide

1. Create a source file such as `lesson1.cpp` and type the example exactly as shown.
2. Build the program with your compiler and run the result once before making changes.
3. Edit one output line to print your own message, then compile and run again.
4. Check that braces, semicolons, and `main` are all in the right place.
5. Finish by explaining in one sentence why every C++ program needs a clear entry point.

Practice Exercises

• Write a variation that prints your name and one reason you are learning C++.
• Create a second version that prints three separate lines instead of two.
• Rebuild the program after introducing one tiny mistake, then fix it and note what the compiler reported.

Coding Challenges

• Type the full program again from scratch without looking, then compare it with the original.
• Make the output slightly more polished while keeping the program short and beginner-friendly.

Mini Practice Tasks

• Rename the file and build it again successfully.
• Add one extra `std::cout` line and rerun the executable.
• Write a one-line summary of what this first program proves.