Capstone: finish the study tracker

What you will build

Combine data, functions, DOM, events, error handling, and persistence into a usable tracker.

Understand the idea first

Combine data, functions, DOM, events, error handling, and persistence into a usable tracker.

Build it step by step

验收流程
1. 添加两条不同记录
2. 标记一条完成
3. 删除一条并可撤销或确认
4. 刷新后状态保留
5. 损坏存储后页面可恢复

1. Open the project from the previous lesson and record its current result.
2. Type and run the example, then complete this task: Finish add, toggle, delete, totals, and persistence; observe another person add one session.
3. Change at least one input, predict the result, and verify it.
4. Create and repair this lesson's typical failure: A page that opens is not complete; every acceptance flow needs observed evidence.

Read the important lines

• Combine data, functions, DOM, events, error handling, and persistence into a usable tracker.
• Read the code as input, processing, and output; point to each part.
• A first successful run is not enough; verify a different input and an edge case.

Common mistakes and what to check

Practice without copying

Finish add, toggle, delete, totals, and persistence; observe another person add one session.

Completion check

• I produced the required visible result
• I can explain the input, processing, and output
• I tested normal, edge, and failure cases