CSSStyleDeclaration.getPropertyPriority()
  The CSSStyleDeclaration.getPropertyPriority() method interface returns
  a DOMString that provides all explicitly set priorities on the CSS
  property.
Syntax
var priority = style.getPropertyPriority(property);
Parameters
- 
    
propertyis aDOMStringrepresenting the property name to be checked. 
Return value
- 
    
priorityis aDOMStringthat represents the priority (e.g."important") if one exists. If none exists, returns the empty string. 
Example
  The following JavaScript code checks whether margin is marked as important
  in a CSS selector rule:
var declaration = document.styleSheets[0].cssRules[0].style;
var isImportant = declaration.getPropertyPriority('margin') === 'important';
Specifications
| Specification | 
|---|
| CSS Object Model (CSSOM)  # dom-cssstyledeclaration-getpropertypriority  | 
Browser compatibility
BCD tables only load in the browser