If / else with sensors — Robotics for kids

Robot tip

True → if, false → else — “put the sensor reading into the condition; only one part runs”

1. Put the reading into the condition: true → the if part, false → the else part.
2. < means strictly less; an equal reading makes it false.
3. else if: check the conditions from the top; the first true one wins. while: repeat until the condition is false.

Use it for: Obstacle-avoiding robots, robot vacuums, coding lessons on conditions and robotics competitions.

Worked example: 🤖 if (distance < 20) { turn right } else { go forward } The distance sensor reads 12 cm. What does the robot do? → turn right

✏️ Practice

Work it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.

🏁 Lesson 23 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 🚧 Obstacle Dodger badge when you pass — and a certificate when you finish all 10 lessons of Part 3 · Programming robots. You can still take the test without signing in.

🖨️ Robotics Worksheet: Robot If / Else

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)