JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>

JavaScript

var values = "width: 423px; height: 281px; margin-bottom: 5px; margin-right: 5px; display: inline-block; vertical-align: bottom; overflow: hidden;"
var pairs = values.split(";");
var pairLength = pairs.length;
for (var i = 0; i < pairLength; i++) {

	var key = pairs[i].split(":")[0];
  var value = pairs[i].split(":")[1];
	if(key.trim()=="width")
  	alert(value.replace("px",""));
  if(key.trim()=="height")
  	alert(value.trim().replace("px",""));
  
  console.log("Key: " + key + " , " + "Value: " + value.replace("px",""));
  
}