JavaScript Class 基础
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About This Exercise
新手可以把 class 理解为“造对象的模板”。
constructor 负责初始化数据，实例方法负责定义行为。
Intermediate⏱ 20-25 min
Learning Objectives
- 定义 class
- 使用 constructor
- 编写实例方法
Scenario
你在写用户系统：用户有名字（属性），还能输出自我介绍（行为）。
这正是 class 最直观的入门场景。
Why Do This
- Frontend JS is not just about knowing the syntax — the key is reliably manipulating the DOM and managing interaction state.
- Break down the event flow (trigger -> handle -> update UI) before coding, and you will make significantly fewer errors.
- Rule-based validation helps you develop a testable frontend mindset.
Hands-on Practice
- Write out the event flow in comments first, then implement the functions.
- Add an edge case branch for invalid input or empty data.
- Explain why each validation rule is needed.
Common Mistakes
- Only testing the happy path without verifying edge inputs or repeated clicks.
- Mixing event binding and state updates together, making future maintenance difficult.
- Console output looks correct but the UI is not actually updated.
Deliverable
A reusable interaction component scaffold (event flow description + key functions + edge case handling).
My Progress
Completed Steps0 / 3
Total Attempts0
Best Score0%
Completion Criteria (Checkable)
Confirm before completing this Lab
Reflection Questions (Recommended)
Describe the event flow of this Lab in 2-3 sentences (trigger -> handle -> update).
What edge case did you add? Why is it easy to miss?
How confident are you with this interaction pattern now?
Tags
JavaScriptES6ClassOOP