56 lines
1.2 KiB
Markdown
56 lines
1.2 KiB
Markdown
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---
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id: 587d7dbb367417b2b2512bac
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title: 刪除開頭和結尾的空白
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challengeType: 1
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forumTopicId: 301362
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dashedName: remove-whitespace-from-start-and-end
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---
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# --description--
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有時字符串周圍存在的空白字符並不是必需的。 字符串的典型處理是刪除字符串開頭和結尾處的空格。
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# --instructions--
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編寫一個正則表達式並使用適當的字符串方法刪除字符串開頭和結尾的空格。
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**注意：** `String.prototype.trim()` 方法在這裏也可以實現同樣的效果，但是你需要使用正則表達式來完成此項挑戰。
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# --hints--
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`result` 應該等於 `Hello, World!`
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```js
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assert(result == 'Hello, World!');
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```
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你不應該使用 `String.prototype.trim()` 方法。
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```js
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assert(!code.match(/\.?[\s\S]*?trim/));
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```
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`result` 變量不應該設置爲等於字符串。
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```js
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assert(!code.match(/result\s*=\s*".*?"/));
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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 hello = " Hello, World! ";
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let wsRegex = /change/; // Change this line
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let result = hello; // Change this line
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```
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# --solutions--
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```js
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let hello = " Hello, World! ";
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let wsRegex = /^(\s+)(.+[^\s])(\s+)$/;
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let result = hello.replace(wsRegex, '$2');
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```
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