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>
79 lines
1.7 KiB
Markdown
79 lines
1.7 KiB
Markdown
---
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id: 587d7da9367417b2b2512b66
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title: 使用 concat 方法组合两个数组
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challengeType: 1
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forumTopicId: 301229
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dashedName: combine-two-arrays-using-the-concat-method
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---
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# --description--
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`Concatenation`意思是将元素连接到尾部。同理，JavaScript 为字符串和数组提供了`concat`方法。对数组来说，在一个数组上调用`concat`方法，然后提供另一个数组作为参数添加到第一个数组末尾，返回一个新数组，不会改变任何一个原始数组。举个例子：
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```js
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[1, 2, 3].concat([4, 5, 6]);
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// 返回新数组 [1, 2, 3, 4, 5, 6]
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```
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# --instructions--
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在`nonMutatingConcat`函数里使用`concat`，将`attach`拼接到`original`尾部，返回拼接后的数组。
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# --hints--
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应该使用`concat`方法。
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```js
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assert(code.match(/\.concat/g));
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```
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不能改变`first`数组。
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```js
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assert(JSON.stringify(first) === JSON.stringify([1, 2, 3]));
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```
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不能改变`second`数组。
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```js
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assert(JSON.stringify(second) === JSON.stringify([4, 5]));
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```
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`nonMutatingConcat([1, 2, 3], [4, 5])`应返回`[1, 2, 3, 4, 5]`。
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```js
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assert(
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JSON.stringify(nonMutatingConcat([1, 2, 3], [4, 5])) ===
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JSON.stringify([1, 2, 3, 4, 5])
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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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function nonMutatingConcat(original, attach) {
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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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var first = [1, 2, 3];
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var second = [4, 5];
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nonMutatingConcat(first, second);
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```
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# --solutions--
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```js
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function nonMutatingConcat(original, attach) {
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// Only change code below this line
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return original.concat(attach);
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// Only change code above this line
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}
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var first = [1, 2, 3];
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var second = [4, 5];
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nonMutatingConcat(first, second);
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```
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