Start with no programming experience. Learn to predict, write, trace, and debug C++ through a simulated delivery robot fleet.
Enter your first code lab ↗Explore the journey →*Local foundation checks. Browser verification and later features are tracked below.
Begin with the ten original lessons. Continue with robot practice, rewards information and lesson hints in sections 11–13, then explore sixteen extension lessons in Steps 14–18. Download complete examples for C++17 compilation.
Inspect all five robots, charge D33P and deliver its 5.5 km route. Advance the mission, track battery use and complete four practice milestones.
This interactive model does not run your C++ code or award XP. Simulation progress resets when the page reloads.
Open fleet simulation →Review reward availability and recommended prerequisites. Instructor reviews, verified XP, badges and prerequisite unlocking are awaiting verification. Practice activities do not earn these awards.
Incorrect practice answers suggest a related topic in the Development log. Repeated errors receive more guidance. The ten original lessons also offer three written hints after your own attempt.
Guidance uses written rules and practice counts in this tab. AI is not connected, no model is trained, and hints do not analyze your edited code or award mastery.
Open the practice tutor →Sixteen additional lessons cover Steps 14–18. Each has a complete example, ten learning activities and public practice tests. Capstones require your own implementation and independent review.
Choose a lesson from the learning journey, then work through its activities in order. The introductory B21K example is available below for the first lesson.
#include <iostream>
int main() {
std::cout << "B21K ready\n";
return 0;
}#include makes the output declarations available. main() is where this program starts. std::cout writes text. \n starts a new line.
Edit the complete lesson program, add source files, and download your work. Live compilation is not available yet. Reset restores the starter for this lesson, so export your draft first if you want to keep it.
No execution result.
Guest code drafts stay in this tab only. Signed-in local drafts are separated by account and lesson on this browser. Download or export them for backup or transfer. The browser compiler is awaiting validation. First use downloads about 30 MB. Browser results are practice evidence, not assessed mastery.
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On your computer, change the message to R07M ready, compile, and compare the output. Then remove the semicolon after the output line, compile again, read the diagnostic, and restore it.
g++ -std=c++17 -Wall -Wextra first-message.cpp -o first-message ./first-message
Explain: Which part prints the robot ID? Why does return 0; not print a zero?
The string literal contains the robot ID. The output statement sends it to std::cout. Returning zero reports successful termination to the calling environment. A missing semicolon makes the program ill-formed and the compiler reports an error.
These are introductory practice tasks. Completing the prediction records practice, not assessed mastery.
Steps 14–18 now offer sixteen additional C++ lessons and two capstone briefs within those lessons. Step 19 adds instructor and privacy tools. Step 20 adds release checks and an operations guide. Hosted verification and the earlier compiler, review, reward and AI gates remain open.
Guest learning stays available. Account data and instructor tools require sign-in.
Use Tab to move between controls, Enter to open a lesson and Space to toggle a button or checkbox. Each learning activity uses a native expandable heading. Code can scroll horizontally without forcing the whole page to scroll. Browser text zoom and reduced-motion settings are respected.
Concept answers are checked without saving a grade. Signed-in prediction practice is saved only when you submit it. Guest editor drafts, hint notes and practice-tutor counts stay in the page. The tutor keeps topic IDs and counts until you clear guidance or reload; it does not retain submitted answers for training. Signed-in drafts stay in browser storage, separated by account. The compiler runs remain disabled until hosted browser verification is complete.
Instructor review receives the exact source and explanation you choose to submit. Reviews and rewards remain disabled pending hosted checks. Account export/deletion is available above. Automatic retention expiry is not configured; server learning data stays until you delete it. Reviews you wrote for other learners remain as attribution for their assessment.
Keyboard, screen-reader and mobile checks are still awaiting supported hosted browser testing. No accessibility-conformance certification is claimed.
Download release and recovery guide