2018-10-10 22:03:03 +00:00
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id: 587d7dbe367417b2b2512bb9
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2020-12-16 07:37:30 +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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challengeType: 0
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2020-09-07 08:11:08 +00:00
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forumTopicId: 301462
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2021-01-13 02:31:00 +00:00
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dashedName: use-for-to-create-a-sass-loop
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2018-10-10 22:03:03 +00:00
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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你可以在 Sass 中使用`@for`循环,它的表现类似与 JavaScript 中的`for`循环。
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2021-01-12 16:22:19 +00:00
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`@for`以两种方式使用:"开始 through 到" 或 "开始 to 结束"。主要区别在于“开始结束”*排除* 结束号码,而“开始结束”*包括* 结束号码。
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2020-12-16 07:37:30 +00:00
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这是一个开始 **到** 结束示例:
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2020-09-07 08:11:08 +00:00
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```scss
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@for $i from 1 through 12 {
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.col-#{$i} { width: 100%/12 * $i; }
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}
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```
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2020-12-16 07:37:30 +00:00
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`#{$i}`部分是将变量(`i`)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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2020-09-07 08:11:08 +00:00
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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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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --instructions--
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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编写`@for`指令,使`$j`的值为从 1(包含)到 6(不包含)。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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它应该创建 5 个名为`.text-1`的 classes 到`.text-5`,其中每个 class 的`font-size`设置为 15px 乘以索引。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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你应使用`@for`指令。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(code.match(/@for /g));
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2018-10-10 22:03:03 +00:00
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```
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2020-12-16 07:37:30 +00:00
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`.text-1`class 的`font-size`应为 15px。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert($('.text-1').css('font-size') == '15px');
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```
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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`.text-2`class 的`font-size`应为 30px。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert($('.text-2').css('font-size') == '30px');
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```
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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`.text-3`class 的`font-size`应为 45px。
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2020-09-07 08:11:08 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert($('.text-3').css('font-size') == '45px');
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```
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2020-09-07 08:11:08 +00:00
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2020-12-16 07:37:30 +00:00
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`.text-4`class 的`font-size`应为 60px。
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2020-09-07 08:11:08 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert($('.text-4').css('font-size') == '60px');
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2018-10-10 22:03:03 +00:00
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```
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2020-08-13 15:24:35 +00:00
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2020-12-16 07:37:30 +00:00
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`.text-5`class 的`font-size`应为 75px。
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2020-09-07 08:11:08 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert($('.text-5').css('font-size') == '75px');
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```
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2020-09-07 08:11:08 +00:00
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2021-01-13 02:31:00 +00:00
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# --seed--
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## --seed-contents--
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```html
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<style type='text/scss'>
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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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2020-12-16 07:37:30 +00:00
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# --solutions--
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2021-01-13 02:31:00 +00:00
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```html
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<style type='text/scss'>
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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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```
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---
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```html
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<style type='text/scss'>
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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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