2021-05-05 10:13:49 -07:00
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---
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id: 587d7db9367417b2b2512ba6
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title: 只指定匹配的下限
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challengeType: 1
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forumTopicId: 301366
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dashedName: specify-only-the-lower-number-of-matches
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---
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# --description--
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可以使用帶有花括號的數量說明符來指定匹配模式的上下限。 但有時候只想指定匹配模式的下限而不需要指定上限。
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爲此,在第一個數字後面跟一個逗號即可。
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例如,要匹配至少出現 `3` 次字母 `a` 的字符串 `hah`,正則表達式應該是 `/ha{3,}h/`。
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```js
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let A4 = "haaaah";
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let A2 = "haah";
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let A100 = "h" + "a".repeat(100) + "h";
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let multipleA = /ha{3,}h/;
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multipleA.test(A4);
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multipleA.test(A2);
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multipleA.test(A100);
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```
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按順序排列,三次 `test` 調用將返回值 `true`,`false` 和 `true`。
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# --instructions--
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修改正則表達式 `haRegex`,匹配包含四個或更多字母 `z` 的單詞 `Hazzah`。
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# --hints--
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你的正則表達式應該使用花括號。
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```js
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assert(haRegex.source.match(/{.*?}/).length > 0);
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```
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你的正則表達式不應匹配字符串 `Hazzah`
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```js
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2021-10-06 08:36:48 -07:00
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haRegex.lastIndex = 0;
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2021-05-05 10:13:49 -07:00
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assert(!haRegex.test('Hazzah'));
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```
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你的正則表達式不應匹配字符串 `Hazzzah`
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```js
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2021-10-06 08:36:48 -07:00
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haRegex.lastIndex = 0;
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2021-05-05 10:13:49 -07:00
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assert(!haRegex.test('Hazzzah'));
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```
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你的正則表達式應該匹配字符串 `Hazzzzah`
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```js
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assert('Hazzzzah'.match(haRegex)[0].length === 8);
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```
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你的正則表達式應該匹配字符串 `Hazzzzzah`
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```js
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assert('Hazzzzzah'.match(haRegex)[0].length === 9);
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```
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你的正則表達式應該匹配字符串 `Hazzzzzzah`
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```js
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assert('Hazzzzzzah'.match(haRegex)[0].length === 10);
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```
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你的正則表達式應該匹配包含 30 個字母 `z` 的 `Hazzah`。
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```js
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assert('Hazzzzzzzzzzzzzzzzzzzzzzzzzzzzzzah'.match(haRegex)[0].length === 34);
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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 haStr = "Hazzzzah";
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let haRegex = /change/; // Change this line
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let result = haRegex.test(haStr);
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```
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# --solutions--
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```js
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let haStr = "Hazzzzah";
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let haRegex = /Haz{4,}ah/; // Change this line
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let result = haRegex.test(haStr);
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```
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