Companion module: the C++ Foundations module is the complete, enriched version of this unit’s material — study these pages together for extra depth, practice sets, and the variation lab.</div>
Unit 01 — Revision Sheet
The whole unit in two pages · Unit index · Quiz
The big picture
A program is a precise list of instructions. The computer executes only
machine code, so a compiler (g++/Clang) translates your C++ source
file (.cpp) into an executable. You develop programs by looping:
EDIT → COMPILE → RUN → (errors or wrong output? back to EDIT)
Fix the first error, recompile, repeat. Compile with warnings on:
g++ -std=c++17 -Wall -Wextra file.cpp -o program.
Anatomy of the minimal program
| Line | Role |
|---|---|
// comment |
note for humans; ignored by the compiler |
#include <iostream> |
bring in the input/output library |
int main() { |
program starts here; { opens the body |
std::cout << "text\n"; |
send text to the console; statement ends with ; |
return 0; |
hand 0 (= success) back to the operating system |
} |
closes main’s body |
Output essentials
| You write | Effect |
|---|---|
<< |
“sends” — chains multiple pieces: cout << "x = " << 42 << "\n"; |
"..." |
string literal; text goes in double quotes |
\n |
newline — the course default |
std::endl |
newline + flush (rarely needed) |
\t |
tab |
\" and \\ |
literal quote / literal backslash |
Common mistakes checklist
- I never ran the executable instead of the
.cpp(or vice versa) by mistake - I pair every
{with a}before compiling - Every statement ends with
; std::beforecoutandendl— every time- I read compiler errors bottom-up: first error first, reported line ≠ mistake line
- Warnings get fixed, never ignored
- Strings that should contain
"or\use\"/\\
Flashcards
| Prompt | Answer |
|---|---|
| What is a program? | A precise list of instructions the computer executes one step at a time |
| What does a compiler do? | Translates C++ source into machine code, producing an executable |
| Edit–compile–run cycle? | Edit the source → compile with g++ → run the executable; errors send you back to edit |
What is main? |
The function where every C++ program starts executing |
What does return 0; mean? |
main reports success (0) to the operating system |
std::cout is…? |
The console output stream; push data into it with << |
\n vs endl? |
Both end the line; endl also flushes the output buffer; prefer \n |
Why compile with -Wall -Wextra? |
Turns on warnings — the compiler flagging suspicious code; fix them all |
| Where does execution start? | In main, at its first statement |
| Comment syntax? | // to end of line (also /* ... */ for multi-line) |