Document.defaultView.getComputedStyle

In the process of using JS, we sometimes need to get the width of the object, if the object itself is open by the content. In the case of unknown width, there is a powerful method Document.defaultView.getComputedStyle () can get the object's CSS style; he returns a CSS style object.

Use: Document.defaultView.getComputedStyle (A, b);
A This object is the object that you want to get.
B, pseudo-class, if not NULL.

div{     width:100px;     font-size:15px;}   

<Div> met him, she became very low low, low to dust, but her heart is happy, from the dust out of flowers to </div> 

Console.log (Document.defaultView.getComputedStyle (d,null). fontSize);

Document.defaultView.getComputedStyle