72 lines
2.0 KiB
Markdown
72 lines
2.0 KiB
Markdown
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---
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id: 56105e7b514f539506016a5e
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title: Count Backwards With a For Loop
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challengeType: 1
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videoUrl: ''
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localeTitle: 用For循环向后计数
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---
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## Description
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<section id="description">只要我们可以定义正确的条件，for循环也可以向后计数。为了向后计数两次，我们需要更改<code>initialization</code> ， <code>condition</code>和<code>final-expression</code> 。我们将从<code>i = 10</code>开始并在<code>i > 0</code>循环。我们将递减<code>i</code> 2每个回路与<code>i -= 2</code> 。 <blockquote> var ourArray = []; <br> for（var i = 10; i> 0; i- = 2）{ <br> ourArray.push（ⅰ）; <br> } </blockquote> <code>ourArray</code>现在包含<code>[10,8,6,4,2]</code> 。让我们改变<code>initialization</code>和<code>final-expression</code>这样我们就可以向后计数两位奇数。 </section>
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## Instructions
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<section id="instructions">使用<code>for</code>循环将奇数从9到1推送到<code>myArray</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: 你应该为此使用<code>for</code>循环。
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testString: 'assert(code.match(/for\s*\(/g).length > 1, "You should be using a <code>for</code> loop for this.");'
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- text: 你应该使用数组方法<code>push</code> 。
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testString: 'assert(code.match(/myArray.push/), "You should be using the array method <code>push</code>.");'
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- text: '<code>myArray</code>应该等于<code>[9,7,5,3,1]</code> 。'
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testString: 'assert.deepEqual(myArray, [9,7,5,3,1], "<code>myArray</code> should equal <code>[9,7,5,3,1]</code>.");'
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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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// Example
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var ourArray = [];
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for (var i = 10; i > 0; i -= 2) {
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ourArray.push(i);
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}
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// Setup
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var myArray = [];
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// Only change code below this line.
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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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