JSFiddle - React, Tailwind, and code Playground

HTML

<body>
     <div id="main">
        <div id="block"></div>
     </div>
    <p id="test"></p>
</body>

CSS

#main {
      position:relative;
      width:400px;
      height:400px;
}

#block {
     position:absolute;
    display:none;
     left:40px;
    top:50px;    
     width:20px;
    height:20px;
}

JavaScript

var testVal = '',
    testVal2 = '';

$('<div  id="block2"></div>').appendTo($('#main')).css({
    position: 'absolute',
     display: 'none',
    width: 30,
    height: 30,
    left: 30,
    top: 30
});

testVal = $('#block').css('left');
testVal2 = $('#block2').css('left');
$('#test').text(testVal+' '+testVal2);