1,HTML source code£º <html> <head> <title>How to use URL</title> </head> <body> <script src="jsjava.js"></script> <script> var url=new URL("mailto:testuser@domain.com"); document.write(url.getDefaultPort()+"<br>"); document.write(url.getProtocol()+"<br>"); document.write(url.getHost()+"<br>"); document.write(url.getPort()+"<br>"); document.write(url.getFile()+"<br>"); document.write(url.getPath()+"<br>"); document.write(url.getQuery()+"<br>"); document.write(url.getRef()+"<br>"); </script> </body> </html> 2,The display:

-1
mailto
null
-1
testuser@domain.com
testuser@domain.com
null
null