learning mark
Array copy:
var a = [1, 2, 3];
var b = a.slice(); // b = [1, 2, 3]
arguments -> array:
Array.prototype.slice.call(arguments); // arguments -> []
http://blog.csdn.net/zpw91/article/details/53705462
http://www.cnblogs.com/web-ed2/archive/2011/07/20/2111678.html