You can edit / change the code and click run button <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>JavaScript Boolean toSource() Method</title> <script>var clicky_site_ids = clicky_site_ids || []; clicky_site_ids.push(101319977);</script><script async src="//static.getclicky.com/js"></script> JavaScript Boolean toSource() Method examples <br><br><br> <script type="text/javascript"> function bus(type, model, color) { this.type= type; this.model= model; this.color= color; } var bus= new bus("TATA","R70 sc","red"); document.write(bus.toSource()); </script>