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>
95 lines
2.4 KiB
Markdown
95 lines
2.4 KiB
Markdown
---
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id: 587d7db7367417b2b2512b9f
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title: 匹配所有的字母和数字
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challengeType: 1
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forumTopicId: 301346
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dashedName: match-all-letters-and-numbers
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---
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# --description--
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使用元字符，可以使用`[a-z]`搜寻字母表中的所有字母。这种元字符是很常见的，它有一个缩写，但这个缩写也包含额外的字符。
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JavaScript 中与字母表匹配的最接近的元字符是`\w`，这个缩写等同于`[A-Za-z0-9_]`。它不仅可以匹配大小写字母和数字，注意，它还会匹配下划线字符（`_`）。
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```js
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let longHand = /[A-Za-z0-9_]+/;
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let shortHand = /\w+/;
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let numbers = "42";
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let varNames = "important_var";
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longHand.test(numbers); // Returns true
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shortHand.test(numbers); // Returns true
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longHand.test(varNames); // Returns true
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shortHand.test(varNames); // Returns true
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```
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# --instructions--
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使用缩写`\w`来计算所有引号中字母和数字字符的数量。
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# --hints--
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你的正则表达式应该使用全局状态修正符。
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```js
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assert(alphabetRegexV2.global);
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```
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正则表达式应该使用元字符 `\w` 匹配字母表里的所有字符。
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```js
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assert(/\\w/.test(alphabetRegexV2.source));
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```
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你的正则表达式应该在`'The five boxing wizards jump quickly.'`中匹配到 31 个字母数字字符。
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```js
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assert(
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'The five boxing wizards jump quickly.'.match(alphabetRegexV2).length === 31
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);
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```
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你的正则表达式应该在`'Pack my box with five dozen liquor jugs.'`中匹配到 32 个字母数字字符。
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```js
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assert(
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'Pack my box with five dozen liquor jugs.'.match(alphabetRegexV2).length ===
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32
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);
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```
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你的正则表达式应该在`'How vexingly quick daft zebras jump!'`中匹配到 30 个字母数字字符。
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```js
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assert(
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'How vexingly quick daft zebras jump!'.match(alphabetRegexV2).length === 30
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);
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```
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你的正则表达式应该在`'123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ.'`中匹配到 36 个字母数字字符。
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```js
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assert(
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'123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ.'.match(alphabetRegexV2)
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.length === 36
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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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let quoteSample = "The five boxing wizards jump quickly.";
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let alphabetRegexV2 = /change/; // Change this line
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let result = quoteSample.match(alphabetRegexV2).length;
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```
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# --solutions--
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```js
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let quoteSample = "The five boxing wizards jump quickly.";
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let alphabetRegexV2 = /\w/g; // Change this line
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let result = quoteSample.match(alphabetRegexV2).length;
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```
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