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CSS Sass Basics Add Reusable Logic to Your Sass Storing Values in Maps

Posted by Melissa L
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Melissa L
Front End Web Development Techdegree Student 10,296 Points

Mixin media query error: Invalid null operation: "null lt 576px".

Not sure why it is giving this message in the console. The error message is: error scss/utilities/_mixins.scss (Line 48: Invalid null operation: "null lt 576px".).

Any help will be greatly appreciated.

mixins:

@mixin mq($break) {
  $value: map-get($breakpoints, $break);
  $sm: map-get($breakpoints, 'sm');

  @if $value < $sm {               /* this is line 48 */
    @media (max-width: $value) { 
      @content;       
    } 
  }
  @else {
    @media (min-width: $value) {
      @content;      
    }        
  }
}

variables:

$break-xs:575px;
$break-s:576px;
$break-m:768px;
$break-l:992px;

$breakpoints:(
  'xs':   575px,  
  'sm':   576px,
  'med':  768px,
  'lg':   992px,
);
JASON LEE
JASON LEE
17,352 Points

I'm getting the exact same error message as well...

1 Answer

JASON LEE
JASON LEE
17,352 Points

I figured it out from my own problem. It has to do with consistently naming the keys in the variable $breakpoints.

So in your __variables.scss file, look at the $breakpoints section and make sure the keys e.g. xs s m l are labeled and applied consistently throughout the entire project and all the folders files. For instance s vs sm or m vs md vs med.

// Breakpoints
$break-xs: 575px;
$break-s: 576px;
$break-m: 768px;
$break-l: 992px;

$breakpoints: (
  'xs': 575px,
  's': 576px,
  'm': 768px,
  'l': 992px,  
);

// Media queries
@mixin mq($break) {
  $value: map-get($breakpoints, $break);
  $sm: map-get($breakpoints, 's');