【日常记录】【CSS】SASS循环的使用-编程知识

【日常记录】【CSS】SASS循环的使用

文章目录

- 1、引言
- 2、安装
- 3、举例
- 4、参考链接

1、引言

目前在任何项目框架中，都会有css 预处理器，目前一般使用 sass、less 这俩其中之一，它可以简化css的书写

Sass 是一款强化 CSS 的辅助工具，它在 CSS 语法的基础上增加了变量 (variables)、嵌套 (nested rules)、混合 (mixins)、导入 (inline imports) 等高级功能，这些拓展令 CSS 更加强大与优雅。使用 Sass 以及 Sass 的样式库（如 Compass）有助于更好地组织管理样式文件，以及更高效地开发项目。

2、安装

npm install -g sass

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这样就是安装正确

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sass --watch .\09_sass.scss 09_output.css
这个表示，监听 09_sass.scss 文件的改变，并且实时输出到 09_output.css 文件

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3、举例

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有 6个右箭头元素，如果写6边就很麻烦， sass 提供的 for 循环

@for 指令可以在限制的范围内重复输出格式，每次按要求（变量的值）对输出结果做出变动。这个指令包含两种格式：@for $var from through ，或者 @for $ var from to ，区别在于 through 与 to 的含义：当使用 through 时，条件范围包含与的值，而使用 to 时条件范围只包含的值不包含的值。另外，$var 可以是任何变量，比如 $i；< start > 和 < end > 必须是整数值。

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<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title><link rel="stylesheet" href="./09_output.css">
</head><body><div class="box">鼠标移入<div class="item"></div><div class="item"></div><div class="item"></div><div class="item"></div><div class="item"></div><div class="item"></div></div>
</body></html>

* {margin: 0;padding: 0;
}
svg {width: 100%;height: 100%;
}
body {height: 100vh;display: flex;align-items: center;
}
.box {position: relative;width: 100px;height: 100px;background-color: aqua;border-radius: 50%;text-align: center;line-height: 100px;cursor: pointer;
}
.box:hover .item {width: 100px;
}
.item {position: absolute;top: 0;left: 0;width: 0px;transition: all 0.4s;overflow: hidden;height: 40px;// transform: rotateX(90deg);background: url("data:image/svg+xml;base64,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")left center/30px 30px repeat;
}$number: 6;
/* 32 */
@for $i from 1 through $number {.item:nth-child(#{$i}) {transform: translateX(#{$i * 100}px);top: #{$i * 20}px;}
}