React Essentials · Final Project · Lesson 25 of 26
Building the Core Feature
Concept
Building the Core Feature
Start with the core interaction, like adding a todo, before adding extras like filtering or persistence.
By the end of this lesson
- Explain the core idea behind Building the Core Feature.
- Predict output before running a change.
- Test one realistic and one unusual input.
- Use the result to make the next decision.
How to study this page
- 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 Building the Core Feature. 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
Implement an addItem function for your project's main list.
Need a nudge?
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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