Get an Object of all Mediaquery Variables

indicator.js

// Create the mediaquery-indicator element
var indicator = document.createElement('div');
indicator.className = 'mq-indicator';
document.body.appendChild(indicator);

// Read Object like content
var mediaQueriesString = window.getComputedStyle(indicator,'::before').content;
/* replace \ cause firefox escape this string */
mediaQueriesString = mediaQueriesString.replace(/\\/g, '');
/* remove first and last quote */
var mediaQueries = mediaQueriesString.substring(1, mediaQueriesString.length-1);
// Convert String to JSON
mediaQueries = JSON.parse(mediaQueries);
// Define Object
var mqWidth = {
  xs: mediaQueries['screen-xs-min'],
  sm: mediaQueries['screen-sm-min'],
  md: mediaQueries['screen-md-min'],
  lg: mediaQueries['screen-lg-min']
};

console.log(mqWidth.lg);

indicator.scss

/* + Set Media Query as Indicator for Javascript */
.mq-indicator {
    &::before {
        //display: none;
        content: '{"screen-xs-min":"#{$screen-xs-min}", "screen-sm-min":"#{$screen-sm-min}", "screen-md-min":"#{$screen-md-min}", "screen-lg-min":"#{$screen-lg-min}"}';
    }
}