Welcome to 2 - Debugging with Patience 🧘
🛠️ Debugging Your Bot in Robocode
Today we focus on watching your robot carefully. You’ll use the Robocode program to run your bot, see what it does, and fix any issues that come up.
🎯 Mission Objective
You will practice testing and improving your robot based on what you observe. This is a coding day, so get ready to experiment, break things, and fix them again. That’s how great robots are made!
🔧 Debugging Tools
Use these simple tricks to track down bugs:
- Print messages using
System.out.println()to see what your bot is doing. - Test your bot after each small change.
- Print out key values to double-check your thinking.
System.out.println("Energy: " + getEnergy());
System.out.println("Heading: " + getDirection());These messages will show up in the terminal when your bot runs.
🕹️ Slow Down the Action
Robocode has built-in tools for slowing things down and pausing the game:
- Drag the TPS slider to reduce the speed.
- Use Pause and Resume to freeze and unfreeze the battle.
- Click Next Turn to advance one frame at a time.
Analyzing your bot’s behavior turn by turn helps you pinpoint exactly when things go wrong.
🔄 Step-by-Step Debugging Example
- Run your bot and observe how it behaves.
- Slow the game down using the TPS slider.
- If something doesn’t make sense, pause and add a debug print.
- Run it again and read the output.
- Try a tiny change. Repeat the test.
Debugging is like being a detective. Use clues to solve the mystery.
⚠️ When Errors Appear
If you get a red error message, don’t panic. Here’s what to do:
- Read the message carefully.
- Look at the line number mentioned.
- Print out variables near that line to help figure out what’s missing.
Exception in thread "main" java.lang.NullPointerException...This means something your code used was empty. Try printing it before the crash.
🏆 Bot Leaderboard: Start Small
You’ll likely begin near the bottom of the rankings. That’s okay! Watch how other bots behave and improve your own strategy.
| Rank | Name |
|---|---|
| 1 | Spin Bot 1.0 |
| 2 | Walls 1.0 |
| 3 | Crazy 1.0 |
| 4 | Track Fire 1.0 |
| 5 | Infinite Mind Pictures Bot 1.0 |
| 6 | Velocity Bot 1.0 |
| 7 | Ram Fire 1.0 |
| 8 | My First Bot 1.0 |
| 9 | Painting Bot 1.0 |
| 10 | Fire 1.0 |
| 11 | Corners 1.0 |
| 12 | Target 1.0 |
💡 Pro Tip
Everyone runs into bugs. Even the best coders! Debugging is not just about fixing errors — it’s how you learn how your robot really works.
Keep asking: “What did I expect to happen? What actually happened?”