69 lines
2.0 KiB
Markdown
69 lines
2.0 KiB
Markdown
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---
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id: cf1111c1c11feddfaeb9bdef
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title: Generate Random Fractions with JavaScript
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challengeType: 1
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videoUrl: ''
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localeTitle: 使用JavaScript生成随机分数
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---
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## Description
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<section id="description">随机数对于创建随机行为很有用。 JavaScript有一个<code>Math.random()</code>函数，它生成一个介于<code>0</code> （含）和不高达<code>1</code> （独占）之间的随机十进制数。因此<code>Math.random()</code>可以返回<code>0</code>但永远不会返回<code>1</code> <strong>Note</strong> <br> <a href="storing-values-with-the-assignment-operator" target="_blank">与使用Equal运算符存储值</a>一样，所有函数调用将在<code>return</code>执行之前解析，因此我们可以<code>return</code> <code>Math.random()</code>函数的值。 </section>
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## Instructions
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<section id="instructions">更改<code>randomFraction</code>以返回随机数而不是返回<code>0</code> 。 </section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: <code>randomFraction</code>应该返回一个随机数。
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testString: 'assert(typeof randomFraction() === "number", "<code>randomFraction</code> should return a random number.");'
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- text: <code>randomFraction</code>返回的<code>randomFraction</code>应该是小数。
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testString: 'assert((randomFraction()+""). match(/\./g), "The number returned by <code>randomFraction</code> should be a decimal.");'
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- text: 您应该使用<code>Math.random</code>来生成随机十进制数。
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testString: 'assert(code.match(/Math\.random/g).length >= 0, "You should be using <code>Math.random</code> to generate the random decimal number.");'
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function randomFraction() {
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// Only change code below this line.
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return 0;
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// Only change code above this line.
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}
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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console.info('after the test');
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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```
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</section>
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