freeCodeCamp/curriculum/challenges/chinese/02-javascript-algorithms-an.../regular-expressions/match-all-letters-and-numbe...

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---
id: 587d7db7367417b2b2512b9f
title: Match All Letters and Numbers
challengeType: 1
videoUrl: ''
localeTitle: 匹配所有字母和数字
---
## Description
<section id="description">使用字符类,您可以使用<code>[az]</code>搜索字母表中的所有字母。这种字符类很常见,它有一个快捷方式,虽然它还包含一些额外的字符。 JavaScript中与字母表匹配的最接近的字符类是<code>\w</code> 。此快捷方式等于<code>[A-Za-z0-9_]</code> 。此字符类匹配大写和小写字母加数字。注意,此字符类还包括下划线字符( <code>_</code> )。 <blockquote>让longHand = / [A-Za-z0-9 _] + /; <br>让shortHand = / \ w + /; <br>让数字=“42”; <br> let varNames =“important_var”; <br> longHand.test数字; //返回true <br> shortHand.test数字; //返回true <br> longHand.testvarNames; //返回true <br> shortHand.testvarNames; //返回true </blockquote>这些快捷方式字符类也称为<code>shorthand character classes</code></section>
## Instructions
<section id="instructions">使用速记字符类<code>\w</code>来计算各种引号和字符串中的字母数字字符数。 </section>
## Tests
<section id='tests'>
```yml
tests:
- text: 你的正则表达式应该使用全局标志。
testString: 'assert(alphabetRegexV2.global, "Your regex should use the global flag.");'
- text: 你的正则表达式应该使用速记字符
testString: 'assert(/\\w/.test(alphabetRegexV2.source), "Your regex should use the shorthand character <code>\w</code> to match all characters which are alphanumeric.");'
- text: 你的正则表达式应该在<code>&quot;The five boxing wizards jump quickly.&quot;</code>找到31个字母数字字符<code>&quot;The five boxing wizards jump quickly.&quot;</code>
testString: 'assert("The five boxing wizards jump quickly.".match(alphabetRegexV2).length === 31, "Your regex should find 31 alphanumeric characters in <code>"The five boxing wizards jump quickly."</code>");'
- text: 你的正则表达式应该在<code>&quot;Pack my box with five dozen liquor jugs.&quot;</code>找到32个字母数字字符<code>&quot;Pack my box with five dozen liquor jugs.&quot;</code>
testString: 'assert("Pack my box with five dozen liquor jugs.".match(alphabetRegexV2).length === 32, "Your regex should find 32 alphanumeric characters in <code>"Pack my box with five dozen liquor jugs."</code>");'
- text: 你的正则表达式应该在<code>&quot;How vexingly quick daft zebras jump!&quot;</code>找到30个字母数字字符<code>&quot;How vexingly quick daft zebras jump!&quot;</code>
testString: 'assert("How vexingly quick daft zebras jump!".match(alphabetRegexV2).length === 30, "Your regex should find 30 alphanumeric characters in <code>"How vexingly quick daft zebras jump!"</code>");'
- text: 你的正则表达式应该在<code>&quot;123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ.&quot;</code>找到36个字母数字字符<code>&quot;123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ.&quot;</code>
testString: 'assert("123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ.".match(alphabetRegexV2).length === 36, "Your regex should find 36 alphanumeric characters in <code>"123 456 7890 ABC def GHI jkl MNO pqr STU vwx YZ."</code>");'
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
let quoteSample = "The five boxing wizards jump quickly.";
let alphabetRegexV2 = /change/; // Change this line
let result = quoteSample.match(alphabetRegexV2).length;
```
</div>
</section>
## Solution
<section id='solution'>
```js
// solution required
```
</section>