Prototype Object toHTML() Method

Syntax:

Object.toHTML(obj);

Return Value :

Returns the return value of obj's toHTML method if it exists, else runs obj through String.interpret method.

Example:

<html>
<head>
<title>Prototype examples</title>
<script type="text/javascript" 
   src="/javascript/prototype.js">
</script>

<script>

var Bookmark = Class.create({
  initialize: function(name, url) {
    this.name = name;
    this.url = url;
  },

  toHTML: function() {
    return '<a href="#{url}">#{name}</a>'.interpolate(this);
  }
});

var api = new Bookmark('Prototype', 'http://prototypejs.org');


function showResult(){
   alert("Test 1: " + Object.toHTML(api));
   alert("Test 2: " + Object.toHTML("Hello world!"));
   alert("Test 3: " + Object.toHTML());
   alert("Test 4: " + Object.toHTML(null));
   alert("Test 5: " + Object.toHTML(undefined));
   alert("Test 6: " + Object.toHTML(true));
   alert("Test 7: " + Object.toHTML(false));
   alert("Test 8: " + Object.toHTML(123));
}

</script>
</head>

<body>

  <p>Click the button to see the result.</p>
  <br />
  <br />
  <input type="button" value="Result" onclick="showResult();"/>

</body>
</html>

To understand it in better way you can Try it yourself.