SASS @for and @while Rule Last Updated : 15 Jul, 2020 Comments Improve Suggest changes Like Article Like Report @for rule is used to count up or down from one number to another and check the section for every number that comes in between the given range. Every number is assigned a given variable name. In order to exclude the last number, use to and in order to include it, use through. Syntax: css @for <variable> from <expression> to <expression> { ... } AND css @for <variable> from <expression> through <expression> { ... } Example: css $gfg: green; @for $i from 1 through 5 { ul:nth-child(2n + #{$i}) { background-color: darken($gfg, $i * 5%); } } Output: ul:nth-child(2n+1) { background-color: #006700; } ul:nth-child(2n+2) { background-color: #004d00; } ul:nth-child(2n+3) { background-color: #003400; } ul:nth-child(2n+4) { background-color: #001a00; } ul:nth-child(2n+5) { background-color: #000100; } @while rule analysis the section only if the given expression is true. The section continues compiling until it returns false, then the section stops compilation. Syntax: css @while <expression> { ... } Example: css @function scale-below($value, $base, $ratio: 2) { @while $value > $base { $value: $value / $ratio; } @return $value; } $normal-font-size: 22px; gfg { font-size: scale-below(20px, 12px); } Output: gfg { font-size: 10px; } Truthiness And Falseness: Some other values can also be used anywhere, true or false are allowed. The values false and null means that the Sass considers them to show falseness and which causes the conditions to fail. Every other value is true. So Sass considers them to succeed with the conditions. Some languages consider some more values for falseness than just false and null, not including Sass in that list. Empty strings, empty lists, and the number 0 are all considered truth in Sass. Comment More infoAdvertise with us Next Article SASS @for and @while Rule S Slash_IT Follow Improve Article Tags : Web Technologies HTML CSS SASS Similar Reads SASS @for Rule The @for rule in SASS is used to count up or down from one number to another and check the section for every number that comes in between the given range. Every number is assigned a variable name that can be accessed in the loop. It can be used in two ways: 1. start through end: In this type, the "s 2 min read Sass | @at-root rule The @at-root rule emits everything inside the rule at the root of the file rather than using normal nesting. It's mostly used during advanced nesting with the SassScript parent selector and selector functions. Syntax: css @at-root <selector> { ... } Example: css @use "sass:selector" 2 min read SASS | @forward rule The @forward rule processes the Sass stylesheets and makes their functions, mixins, and variables available in the cases when the stylesheet is loaded using @use rule. Organizing Sass libraries across many files are made possible, along with providing users to process a single entry point file. Synt 3 min read SASS | Style Rules Just like CSS, style rules are also the base of SASS. It is used similar to CSS. Select the elements to be styled using a selector and then declare it's properties which further affects the look of those elements. Example: Sass Code: css .header padding: 3px 10px font-size: 40px font-family: sans-se 3 min read Sass @extend Rule The sass @extend rule can be used when it is necessary for a class to have the styles of another class, along with its own specific styles. This rule tells Sass that one selector should inherit the class from another selector.Syntax:@extend <selector>Example: This example shows the use of the 3 min read Like