67 lines
1.9 KiB
Markdown
67 lines
1.9 KiB
Markdown
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---
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id: 56533eb9ac21ba0edf2244ac
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title: Increment a Number with JavaScript
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challengeType: 1
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videoUrl: ''
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localeTitle: 使用JavaScript增加数字
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---
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## Description
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<section id="description">您可以轻松地<dfn>增加</dfn>或添加一个变量与<code>++</code>运算符。 <code>i++;</code>相当于<code>i = i + 1;</code> <strong>注意</strong> <br>整行成为<code>i++;</code> ，消除了对等号的需要。 </section>
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## Instructions
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<section id="instructions">更改代码以在<code>myVar</code>上使用<code>++</code>运算符。 <strong>暗示</strong> <br>了解有关<a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Increment_()" target="_blank">算术运算符的</a>更多信息<a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators#Increment_()" target="_blank">- 增量（++）</a> 。 </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>myVar</code>应该等于<code>88</code>
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testString: 'assert(myVar === 88, "<code>myVar</code> should equal <code>88</code>");'
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- text: <code>myVar = myVar + 1;</code>应该改变
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testString: 'assert(/var\s*myVar\s*=\s*87;\s*\/*.*\s*([+]{2}\s*myVar|myVar\s*[+]{2});/.test(code), "<code>myVar = myVar + 1;</code> should be changed");'
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- text: 使用<code>++</code>运算符
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testString: 'assert(/[+]{2}\s*myVar|myVar\s*[+]{2}/.test(code), "Use the <code>++</code> operator");'
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- text: 不要更改行上方的代码
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testString: 'assert(/var myVar = 87;/.test(code), "Do not change code above the line");'
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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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var myVar = 87;
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// Only change code below this line
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myVar = myVar + 1;
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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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