1,HTML source code£º <html> <head> <title>How to use Set</title> </head> <body> <script src="jsjava.js"></script> <script> var s=new HashSet(); var a=["a","b","a","b","c"]; s.add(a); document.write(s); </script> </body> </html> 2,The display:

a,b,a,b,c