ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
101 lines
2.2 KiB
Markdown
101 lines
2.2 KiB
Markdown
---
|
|
id: 587d7b7c367417b2b2512b19
|
|
title: 修改嵌套在对象中的对象
|
|
challengeType: 1
|
|
forumTopicId: 301164
|
|
dashedName: modify-an-object-nested-within-an-object
|
|
---
|
|
|
|
# --description--
|
|
|
|
现在我们来看一个稍复杂的对象。在对象中，我们也可以嵌套任意层数的对象，对象的属性值可以是 JavaScript 支持的任意类型，包括数组和其他对象。请看以下例子：
|
|
|
|
```js
|
|
let nestedObject = {
|
|
id: 28802695164,
|
|
date: 'December 31, 2016',
|
|
data: {
|
|
totalUsers: 99,
|
|
online: 80,
|
|
onlineStatus: {
|
|
active: 67,
|
|
away: 13
|
|
}
|
|
}
|
|
};
|
|
```
|
|
|
|
`nestedObject` 有 3 个属性：`id`（属性值为数字）、`date`（属性值为字符串）、`data`（属性值为嵌套的对象）。虽然对象中的数据可能很复杂，我们仍能使用上一个挑战中讲到的写法来访问我们需要的信息。如果我们想把嵌套在 `onlineStatus` 中 `busy` 的属性值改为 `10`，可以用点号表示法来这样实现：
|
|
|
|
```js
|
|
nestedObject.data.onlineStatus.busy = 10;
|
|
```
|
|
|
|
# --instructions--
|
|
|
|
我们已经定义了一个 `userActivity` 对象，它包含了另一个对象。请将 `online` 的属性值改为 `45`。
|
|
|
|
# --hints--
|
|
|
|
`userActivity` 应包含 `id`、`date` 和 `data` 属性。
|
|
|
|
```js
|
|
assert(
|
|
'id' in userActivity && 'date' in userActivity && 'data' in userActivity
|
|
);
|
|
```
|
|
|
|
`userActivity` 应包含 `data` 属性，其属性值应为包含 `totalUsers` 和 `online` 属性的对象。
|
|
|
|
```js
|
|
assert('totalUsers' in userActivity.data && 'online' in userActivity.data);
|
|
```
|
|
|
|
`userActivity` 的 `data` 属性值中的 `online` 属性值应被改为 `45`。
|
|
|
|
```js
|
|
assert(userActivity.data.online === 45);
|
|
```
|
|
|
|
应使用点号表示法或方括号表示法来修改 `online` 属性值。
|
|
|
|
```js
|
|
assert.strictEqual(code.search(/online: 45/), -1);
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
let userActivity = {
|
|
id: 23894201352,
|
|
date: 'January 1, 2017',
|
|
data: {
|
|
totalUsers: 51,
|
|
online: 42
|
|
}
|
|
};
|
|
|
|
// Only change code below this line
|
|
|
|
// Only change code above this line
|
|
|
|
console.log(userActivity);
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
let userActivity = {
|
|
id: 23894201352,
|
|
date: 'January 1, 2017',
|
|
data: {
|
|
totalUsers: 51,
|
|
online: 42
|
|
}
|
|
};
|
|
|
|
userActivity.data.online = 45;
|
|
```
|