Sass - @if Directive

Quiz

Description

The @if directive accepts the SassScript expressions and uses the nested styles whenever the result of the expression is anything other than false or null.

Syntax

@if expression {  //CSS codes are written here }

Example

The following example demonstrates the use of @if directive in the SCSS file −

<html>
   <head>
      <title>Control Directives & Expressions</title>
      <link rel = "stylesheet" type = "text/css" href = "style.css"/>
   </head>

   <body>
      <div class = "container">
         <h2>Example for Control Directive & Expressions</h2>
         <p>SASS stands for Syntactically Awesome Stylesheet. </p>
      </div>
   </body>
</html>

Next, create file style.scss.

style.scss

p {
   @if 10 + 10 == 20   { border: 1px dotted;   }
   @if 7 < 2     { border: 2px solid;  }
   @if null    { border: 3px double; }
}

You can tell SASS to watch the file and update the CSS whenever SASS file changes, by using the following command −

sass --watch C:\ruby\lib\sass\style.scss:style.css

Next, execute the above command; it will create the style.css file automatically with the following code −

style.css

p {
   border: 1px dotted; 
}

Output

Let us carry out the following steps to see how the above given code works −

Save the above given html code in @if_directive.html file.
Open this HTML file in a browser, an output as below gets displayed

sass_control_directives_expressions.htm

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