Use @for to Create a Sass Loop
Problem Explanation
- The basic syntax of
@for
loop in SASS:
- For - through loop:
@for $i from <start number> through <end number> {
// some CSS
}
- For - to loop:
@for $i from <start number> to <end number> {
// some CSS
}
Notice that the main difference is that “start to end” excludes the end number, and “start through end” includes the end number.
2. For example:
- For - through loop:
@for $i from 1 through 3 {
// some CSS
}
// 1 2 3
- For - to loop:
@for $i from 1 to 3 {
// some CSS
}
// 1 2
- Guideline from SASS Guideline
The @for
loop might be useful when combined with CSS’ :nth-*
pseudo-classes. Except for these scenarios, prefer an @each
loop if you have to iterate over something.
@for $i from 1 through 10 {
.foo:nth-of-type(#{$i}) {
border-color: hsl($i * 36, 50%, 50%);
}
}
Always use $i
as a variable name to stick to the usual convention and unless you have a really good reason to, never use the to
keyword: always use through
. Many developers do not even know Sass offers this variation; using it might lead to confusion.
Also be sure to respect those guidelines to preserve readability:
- Always an empty new line before
@for
; - Always an empty new line after the closing brace (}) unless the next line is a closing brace (}).
Solutions
Solution 1 (Click to Show/Hide)
<style type='text/scss'>
@for $j from 1 through 5 {
.text-#{$j} { font-size: 15px * $j; }
}
</style>
<p class="text-1">Hello</p>
<p class="text-2">Hello</p>
<p class="text-3">Hello</p>
<p class="text-4">Hello</p>
<p class="text-5">Hello</p>
The solution above will generate the following CSS:
.text-1 {
font-size: 15px;
}
.text-2 {
font-size: 30px;
}
.text-3 {
font-size: 45px;
}
.text-4 {
font-size: 60px;
}
.text-5 {
font-size: 75px;
}