JS to determine whether the browser support html5_javascript skills

Now HTML5 seems to be getting popular, some front-end experts for compatibility considerations, will be added to the Web page to judge the client browser code, know whether the user browser support HTML5, the following share think I use 2 ways

Method One,

<script>  
function checkhHtml5 () {   
if (typeof (Worker)!== "undefined") {   alert ("Support HTML5");   }   else {   alert ("HTML5 not Supported");   } 
</script>

Method Two,

<canvas id= "Canvas" ></canvas>

<script>   if (!document.getelementbyid ("Canvas"). GetContext) {     alert ("Do not support HTML5");   }   else{  alert ("Support HTML5");  </script>

If there is a better way, please contact me! Thank you