72 lines
1.7 KiB
Markdown
72 lines
1.7 KiB
Markdown
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---
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id: 587d7db5367417b2b2512b96
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title: 匹配字母表中的字母
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challengeType: 1
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forumTopicId: 301354
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dashedName: match-letters-of-the-alphabet
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---
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# --description--
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瞭解瞭如何使用字符集（<dfn>character sets</dfn>）來指定要匹配的一組字符串，但是有時需要匹配大量字符（例如，字母表中的每個字母）。 有一種寫法可以讓實現這個功能變得簡短。
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在字符集中，可以使用連字符（`-`）來定義要匹配的字符範圍。
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例如，要匹配小寫字母 `a` 到 `e`，你可以使用 `[a-e]`。
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```js
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let catStr = "cat";
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let batStr = "bat";
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let matStr = "mat";
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let bgRegex = /[a-e]at/;
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catStr.match(bgRegex);
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batStr.match(bgRegex);
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matStr.match(bgRegex);
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```
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按順序排列，三次 `match` 調用將返回值 `["cat"]`，`["bat"]` 和 `null`。
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# --instructions--
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匹配字符串 `quoteSample` 中的所有字母。
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**注意**：一定要同時匹配大小寫字母。
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# --hints--
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你的正則表達式 `alphabetRegex` 應該匹配 35 項。
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```js
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assert(result.length == 35);
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```
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你的正則表達式 `alphabetRegex` 應該使用全局標識。
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```js
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assert(alphabetRegex.flags.match(/g/).length == 1);
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```
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你的正則表達式 `alphabetRegex` 應該使用忽略大小寫標誌。
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```js
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assert(alphabetRegex.flags.match(/i/).length == 1);
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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 quick brown fox jumps over the lazy dog.";
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let alphabetRegex = /change/; // Change this line
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let result = alphabetRegex; // Change this line
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```
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# --solutions--
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```js
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let quoteSample = "The quick brown fox jumps over the lazy dog.";
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let alphabetRegex = /[a-z]/gi; // Change this line
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let result = quoteSample.match(alphabetRegex); // Change this line
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```
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