Append dynamic HTML block to an existing div tag using pure JavaScript?

Suppose we have the following div tag with an id parent-box and we want to insert custom HTML code inside it using JavaScript then we can use the below-given snippet.

<div id="parent-box">
</div >

JavaScript Code to append HTML block to the above tag

var htmlCode = '<div class="custom-content">' +
				'	<h2 class="heading">Hi, I am Custom Heading Text</h2>' +
                '	<div class="another-div">' +
                '	<div class="image-box">' +
				'		<img id="responsive-image" src="cool-image.png">' +
                '	</div>' +
                '	</div>' +
                '</div>';
					
document.getElementById("parent-box").innerHTML = htmlCode;