1
2<h1>"My number: " <span id="myText"></span></h1>
3
4<script>
5
6	//You can use an IIFE (Immediately Invoked Function Expression)
7	(() => {
8  		var number = "123";
9		document.getElementById("myText").innerHTML = number;
10	})();
11</script>

1var name="kieran";
2document.getElementById("output").innerHTML=name;
3
4and the html code would be: 
5
6<p id="output"></p>
7

1// Plain Javascript Example
2var $jsName = document.querySelector('.name');
3var $jsValue = document.querySelector('.jsValue');
4
5$jsName.addEventListener('input', function(event){
6  $jsValue.innerHTML = $jsName.value;
7}, false);
8
9
10// JQuery example
11var $jqName = $('.name');
12var $jqValue = $('.jqValue');
13
14$jqName.on('input', function(event){
15  $jqValue.html($jqName.val());
16});