2018-10-10 22:03:03 +00:00
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id: 587d7dbe367417b2b2512bb9
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challengeType: 0
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2020-09-07 08:11:08 +00:00
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forumTopicId: 301462
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2020-10-01 15:54:21 +00:00
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title: 使用 @for 创建一个 Sass 循环
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2018-10-10 22:03:03 +00:00
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---
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## Description
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2020-09-07 08:11:08 +00:00
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<section id='description'>
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你可以在 Sass 中使用<code>@for</code>循环,它的表现类似与 JavaScript 中的<code>for</code>循环。
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<code>@for</code>以两种方式使用:"start through end" 或 "start to end"。主要区别在于“开始结束”<em> 排除 </em> 结束号码,而“开始结束”<em> 包括 </em> 结束号码。
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这是一个开始 <b> 到 </b> 结束示例:
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```scss
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@for $i from 1 through 12 {
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.col-#{$i} { width: 100%/12 * $i; }
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}
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```
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<code>#{$i}</code>部分是将变量(<code>i</code>)与文本组合成字符串的语法。当 Sass 文件转换为 CSS 时,它看起来像这样:
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```scss
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.col-1 {
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width: 8.33333%;
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}
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.col-2 {
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width: 16.66667%;
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}
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...
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.col-12 {
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width: 100%;
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}
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```
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这是创建网格布局的有效方法。现在,你有 12 个可用作 CSS classes 的列宽选项。
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</section>
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2018-10-10 22:03:03 +00:00
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## Instructions
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2020-09-07 08:11:08 +00:00
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<section id='instructions'>
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编写<code>@for</code>指令,使<code>$j</code>的值为从 1(包含)到 6(不包含)。
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它应该创建 5 个名为<code>.text-1</code>的 classes 到<code>.text-5</code>,其中每个 class 的<code>font-size</code>设置为 15px 乘以索引。
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</section>
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2018-10-10 22:03:03 +00:00
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## Tests
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<section id='tests'>
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```yml
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tests:
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2020-09-07 08:11:08 +00:00
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- text: 你应使用<code>@for</code>指令。
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testString: assert(code.match(/@for /g));
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- text: <code>.text-1</code>class 的<code>font-size</code>应为 15px。
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testString: assert($('.text-1').css('font-size') == '15px');
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- text: <code>.text-2</code>class 的<code>font-size</code>应为 30px。
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testString: assert($('.text-2').css('font-size') == '30px');
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- text: <code>.text-3</code>class 的<code>font-size</code>应为 45px。
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testString: assert($('.text-3').css('font-size') == '45px');
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- text: <code>.text-4</code>class 的<code>font-size</code>应为 60px。
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testString: assert($('.text-4').css('font-size') == '60px');
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- text: <code>.text-5</code>class 的<code>font-size</code>应为 75px。
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2020-02-17 16:40:55 +00:00
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testString: assert($('.text-5').css('font-size') == '75px');
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2018-10-10 22:03:03 +00:00
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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='html-seed'>
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```html
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<style type='text/sass'>
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</style>
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<p class="text-1">Hello</p>
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<p class="text-2">Hello</p>
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<p class="text-3">Hello</p>
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<p class="text-4">Hello</p>
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<p class="text-5">Hello</p>
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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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2020-09-07 08:11:08 +00:00
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```html
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<style type='text/sass'>
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@for $i from 1 through 5 {
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.text-#{$i} { font-size: 15px * $i; }
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}
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</style>
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<p class="text-1">Hello</p>
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<p class="text-2">Hello</p>
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<p class="text-3">Hello</p>
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<p class="text-4">Hello</p>
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<p class="text-5">Hello</p>
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2018-10-10 22:03:03 +00:00
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```
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2020-08-13 15:24:35 +00:00
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2020-09-07 08:11:08 +00:00
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```html
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<style type='text/sass'>
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@for $i from 1 to 6 {
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.text-#{$i} { font-size: 15px * $i; }
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}
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</style>
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<p class="text-1">Hello</p>
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<p class="text-2">Hello</p>
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<p class="text-3">Hello</p>
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<p class="text-4">Hello</p>
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<p class="text-5">Hello</p>
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```
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</section>
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