how to pass data from an html input to a function code example

Example 1: How to Pass Parameter in JavaScript Function From Html

<!DOCTYPE html>
<html>
<head>
	<title>function parameters javascript</title>
</head>
<body>
<button onclick="myfunctionName('rohan')">Click</button>

<script type="text/javascript">
	
	function myfunctionName(a){

		alert(a);
		
	}

</script>
</body>
</html>

Example 2: javascript function with input value

<button class="btn btn-primary" onclick="transmit({search: document.getElementById('search_id').value});">
	<span class="glyphicon glyphicon-search"></span>
</button>