JavaScript Fundamentals · Functions · Lesson 13 of 48
Parameters and Return Values
Concept
Parameters and Return Values
Parameters are placeholders for input values. return sends a result back to wherever the function was called.
As soon as return runs, the function stops immediately — any code written after it in the same block never executes.
- Explain the core idea behind Parameters and Return Values.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
- 1. Read one concept.
- 2. Change the example.
- 3. Run, compare, and explain.
- 4. Complete the challenge below.
Self-check before continuing
Without looking at the example, describe what changes when you modify one input in Parameters and Return Values. Then reopen the editor and prove your explanation with a small test.
You are ready to continue when you can predict, test, and explain the result.
Your turn
Write a function that takes three numbers and returns their average.
Ask about this lesson or your next move. The guide explains the path without taking the work away from you.
Ready for the next lesson?
Mark this lesson complete when you have finished the exercise.
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