动手做Get your hands on it
练习跟着课文走 —— 每节课尾都有本课的练习。这一页是全部练习的总库，想集中刷题的时候来。 每个练习都写清了它来自哪一节，卡住了就回去看那一节。Practice follows the lessons — every lesson ends with the exercises for that lesson. This page is the whole library, for when you want to drill in one sitting. Each exercise names the lesson it came from, so you can go back when you stall.
已筛到你正在学的《地基 · 项目与语言》。想看全部就点上面的「全部」。Filtered to Foundations · project and language — the course you are on. Use “All” above to see everything.
练习Exercises
筛出 7 个练习（共 148 个）。Showing 7 of 148.下面是 node-subgraph/package.json 的骨架，挖掉了三个决定项目行为的值。 照真实文件补回来。
Below is the skeleton of node-subgraph/package.json with three values removed. Each one decides how the project behaves. Put them back the way the real file has them.
这是 NoteManager 里三个 handler 的真实代码， 挖掉了决定行为的关键词。想清楚每个操作要「保留多少条」再填。
This is the real code of the three handlers in NoteManager, with the words that decide the behaviour removed. Before you fill each one in, work out how many items that operation has to keep.
这一类 bug 最难查，因为它不报错。 先看现象，判断类型，再找病灶 —— 别跳步。
This kind of bug is the hardest to find, because it reports no error. Read the symptom, classify it, then locate it. Do not skip a step.
这是 subgraph 里真实的 DataLoader 批量加载函数。 两个空都关系到「异步 + 数组」的固定套路。
This is the real DataLoader batch function from the subgraph. Both blanks are part of the fixed pattern for async work over an array.
你在 node-subgraph/ 里跑 npm start, 服务器起不来。报错很长，但关键信息只有两行。
You run npm start inside node-subgraph/ and the server does not come up. The error is long, but only two lines of it matter.
这是 NoteTable 真实的 props 类型。 三个空：一个数组类型、一个函数类型的参数、一个函数类型的返回值。
This is the real props type of NoteTable. Three blanks: an array type, a parameter of a function type, and the return value of a function type.
两处真实的泛型用法。想清楚「TypeScript 能不能自己推断出来」。
Two real uses of generics. For each one, work out whether TypeScript can infer it on its own.