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>
61 lines
1.3 KiB
Markdown
61 lines
1.3 KiB
Markdown
---
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id: bd7123c9c452eddfaeb5bdef
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title: 使用方括号查找字符串中的第N个字符到最后一个字符
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cw4vkh9'
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forumTopicId: 18344
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dashedName: use-bracket-notation-to-find-the-nth-to-last-character-in-a-string
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---
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# --description--
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我们既可以获取字符串的最后一个字符，也可以用获取字符串的倒数第N个字符。
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例如，你可以这样`firstName[firstName.length - 3]`操作来获得`var firstName = "Charles"`字符串中的倒数第三个字符。
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# --instructions--
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使用<dfn>方括号</dfn>来获得`lastName`字符串中的倒数第二个字符。
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**提示**
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如果你遇到困难了，不妨看看`thirdToLastLetterOfFirstName`变量是如何做到的。
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# --hints--
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`secondToLastLetterOfLastName`应该是"c"。
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```js
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assert(secondToLastLetterOfLastName === 'c');
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```
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你需要使用`.length`获取倒数第二个字符。
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```js
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assert(code.match(/\.length/g).length === 2);
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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(v){return v;})(secondToLastLetterOfLastName);
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```
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## --seed-contents--
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```js
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// Setup
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var lastName = "Lovelace";
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// Only change code below this line
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var secondToLastLetterOfLastName = lastName; // Change this line
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```
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# --solutions--
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```js
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var lastName = "Lovelace";
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var secondToLastLetterOfLastName = lastName[lastName.length - 2];
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```
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