4-use-if-and-else-to-add-logic-to-your-styles.html

<!-- Use @if and @else to Add Logic To Your Styles
The @if directive in Sass is useful to test for a specific case - it works just like the if statement in JavaScript.

@mixin make-bold($bool) {
@if $bool == true {
font-weight: bold;
}
}
And just like in JavaScript, @else if and @else test for more conditions:

@mixin text-effect($val) {
@if $val == danger {
color: red;
}
@else if $val == alert {
color: yellow;
}
@else if $val == success {
color: green;
}
@else {
color: black;
}
}
Create a mixin called border-stroke that takes a parameter $val. The mixin should check for the following conditions using @if, @else if, and @else:

light - 1px solid black
medium - 3px solid black
heavy - 6px solid black
If $val is not light, medium, or heavy, the border should be set to none.

- Your code should declare a mixin named border-stroke which has a parameter named $val.
- Your mixin should have an @if statement to check if $val is light, and to set the border to 1px solid black.
- Your mixin should have an @else if statement to check if $val is medium, and to set the border to 3px solid black.
- Your mixin should have an @else if statement to check if $val is heavy, and to set the border to 6px solid black.
- Your mixin should have an @else statement to set the border to none.
-->
<style type='text/scss'>

  @mixin border-stroke($val) {
    @if $val == light {
      border: 1px solid black;
    } @else if $val == medium {
      border: 3px solid black;
    } @else if $val == heavy {
      border: 6px solid black;
    } @else {
      border: none;
    }
  }

  #box {
    width: 150px;
    height: 150px;
    background-color: red;
    @include border-stroke(medium);
  }

</style>

<div id="box"></div>