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>
153 lines
3.2 KiB
Markdown
153 lines
3.2 KiB
Markdown
---
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id: 8d1323c8c441eddfaeb5bdef
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title: 创建一个Set类
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challengeType: 1
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videoUrl: ''
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dashedName: create-a-set-class
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---
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# --description--
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在接下来的几个练习中，我们将创建一个函数来模拟一个名为“Set”的数据结构。 Set类似于数组，但不能包含重复值。 Set的典型用途是简单地检查项目是否存在。这可以用对象实现，例如：
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> var set = new Object（）;
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> set.foo = true;
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> //看看我们的集合中是否存在foo：
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> console.log（set.foo）// true
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在接下来的几个练习中，我们将从头开始构建一个全功能的Set。对于本练习，只要该值中尚不存在该值，就创建一个将值添加到set集合的函数。例如：
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> this.add = function（element）{
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> //一些代码来为集合添加值
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> }
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如果成功添加该值，则该函数应返回`true`否则返回`false` 。
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# --hints--
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您的`Set`类应该有一个`add`方法。
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```js
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assert(
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(function () {
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var test = new Set();
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return typeof test.add === 'function';
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})(),
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'Your <code>Set</code> class should have an <code>add</code> method.'
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);
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```
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您的`add`方法不应添加重复值。
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```js
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assert(
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(function () {
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var test = new Set();
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test.add('a');
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test.add('b');
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test.add('a');
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var vals = test.values();
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return vals[0] === 'a' && vals[1] === 'b' && vals.length === 2;
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})(),
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'Your <code>add</code> method should not add duplicate values.'
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);
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```
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成功添加值后， `add`方法应返回`true` 。
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```js
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assert(
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(function () {
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var test = new Set();
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var result = test.add('a');
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return result != undefined && result === true;
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})(),
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'Your <code>add</code> method should return <code>true</code> when a value has been successfully added.'
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);
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```
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`add`重复值时， `add`方法应返回`false` 。
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```js
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assert(
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(function () {
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var test = new Set();
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test.add('a');
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var result = test.add('a');
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return result != undefined && result === false;
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})(),
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'Your <code>add</code> method should return <code>false</code> when a duplicate value is added.'
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);
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```
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# --seed--
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## --seed-contents--
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```js
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class Set {
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constructor() {
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// Dictionary will hold the items of our set
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this.dictionary = {};
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this.length = 0;
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}
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// This method will check for the presence of an element and return true or false
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has(element) {
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return this.dictionary[element] !== undefined;
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}
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// This method will return all the values in the set
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values() {
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return Object.values(this.dictionary);
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}
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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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class Set {
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constructor() {
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this.dictionary = {};
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this.length = 0;
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}
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has(element) {
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return this.dictionary[element] !== undefined;
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}
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values() {
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return Object.values(this.dictionary);
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}
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add(element) {
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if (!this.has(element)) {
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this.dictionary[element] = element;
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this.length++;
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return true;
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}
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return false;
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}
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remove(element) {
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if (this.has(element)) {
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delete this.dictionary[element];
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this.length--;
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return true;
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}
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return false;
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}
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size() {
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return this.length;
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}
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}
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```
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