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>
160 lines
2.9 KiB
Markdown
160 lines
2.9 KiB
Markdown
---
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id: 56bbb991ad1ed5201cd392d0
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title: 新建 JavaScript 对象
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cWGkbtd'
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forumTopicId: 16769
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dashedName: build-javascript-objects
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---
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# --description--
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你之前可能听说过对象`object`。
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对象和数组很相似，数组是通过索引来访问和修改数据，而对象是通过属性来访问和修改数据。
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对象适合用来存储结构化数据，就和真实世界的对象一模一样，比如一只猫。
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这是一个对象的示例：
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```js
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var cat = {
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"name": "Whiskers",
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"legs": 4,
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"tails": 1,
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"enemies": ["Water", "Dogs"]
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};
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```
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在这个示例中所有的属性以字符串的形式储存，例如，`"name"`、`"legs"`和`"tails"`。但是，你也可以使用数字作为属性，你甚至可以省略字符串属性的引号，如下所示：
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```js
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var anotherObject = {
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make: "Ford",
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5: "five",
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"model": "focus"
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};
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```
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但是，如果你的对象具有任何非字符串属性，JavaScript 将自动将它们转换为字符串类型。
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# --instructions--
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创建一个叫做`myDog`的对象，它里面有这些属性：`"name"`、`"legs"`、`"tails"`、`"friends"`。
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你可以设置对象属性为任何值，只需要确保`"name"`是字符串，`"legs"`和`"tails"`是数字，`"friends"`是数组。
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# --hints--
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`myDog`应该包含`name`属性，并且是一个字符串`string`。
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```js
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assert(
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(function (z) {
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if (
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z.hasOwnProperty('name') &&
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z.name !== undefined &&
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typeof z.name === 'string'
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) {
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return true;
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} else {
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return false;
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}
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})(myDog)
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);
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```
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`myDog`应该包含`legs`属性，并且是一个数字`number`。
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```js
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assert(
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(function (z) {
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if (
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z.hasOwnProperty('legs') &&
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z.legs !== undefined &&
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typeof z.legs === 'number'
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) {
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return true;
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} else {
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return false;
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}
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})(myDog)
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);
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```
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`myDog`应该包含`tails`属性，并且是一个数字`number`。
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```js
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assert(
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(function (z) {
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if (
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z.hasOwnProperty('tails') &&
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z.tails !== undefined &&
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typeof z.tails === 'number'
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) {
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return true;
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} else {
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return false;
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}
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})(myDog)
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);
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```
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`myDog`应该包含`friends`属性，并且是一个数组`array`。
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```js
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assert(
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(function (z) {
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if (
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z.hasOwnProperty('friends') &&
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z.friends !== undefined &&
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Array.isArray(z.friends)
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) {
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return true;
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} else {
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return false;
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}
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})(myDog)
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);
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```
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`myDog`应该只包含给出的属性。
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```js
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assert(
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(function (z) {
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return Object.keys(z).length === 4;
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})(myDog)
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);
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```
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# --seed--
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## --after-user-code--
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```js
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(function(z){return z;})(myDog);
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```
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## --seed-contents--
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```js
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var myDog = {
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// Only change code below this line
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// Only change code above this line
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};
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```
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# --solutions--
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```js
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var myDog = {
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"name": "Camper",
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"legs": 4,
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"tails": 1,
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"friends": ["everything!"]
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};
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```
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