JavaScript/functions.html

<!DOCTYPE html>
<html>
   <head>
       <meta charset="utf-8">
       <title>Demo Functions</title>
   </head>
   <body>
   
      <script type="text/javascript">
			"use strict";
	  
            function hello(somebody) {
				return 'Hello ' + somebody;
			}
			
			// Parameter may be of any type
			document.write( '<br/>--- Parameter may be of any type ---<br/>' );
			
			document.write( hello('Somebody') + '<br/>');
			document.write( hello(2)  + '<br/>' ); 
			document.write( hello(null)  + '<br/>' );
			document.write( hello()  + '<br/>' );
			
			document.write( '<br/>' );
			
			// Parameter counts may exceed defined
			document.write( '<br/>--- Exceed number of parameters ---<br/>' );
			
			document.write( hello('Somebody', 23)  + '<br/>' );
			
			
			// Anonymous function
			document.write( '<br/>--- Function Literals ---<br/>' );
			
			var func = function() {
				return 'Anonymous function';
			}
			
			document.write( func()  + '<br/>' );
			
			// dynamic list of parameters
			document.write( '<br/>--- Dynamic list of parameters ---<br/>' );
			
			func = function() {
				console.log('Function called with ' + arguments.length + ' arguments');
				for(var key in arguments) {
					document.write( key + ' -> ' + arguments[key] + '<br/>' );
				};
			}
			
			func();
			func(1);
			func('Somebody', 123);

			
			// Function without return
			document.write( '<br/>--- Function without return ---<br/>' );
			
			document.write( func()  + '<br/>' );
			
			// Nested Functions
			document.write( '<br/>--- Nested Functions ---<br/>' );

			function hypotenuse(a, b) {
               function square(x) { return x*x; }
               return Math.sqrt(square(a) + square(b));
            }
			document.write( hypotenuse(3, 5) + '<br/>' );
      </script>
   </body>
<html>