Question

Is there any way to create Set data structure(Unique Collections) like java in javascript?

Answer 1

For a set of strings, I would just use a object with the value true.

var obj = {};
obj["foo"] = true;
obj["bar"] = true;

if(obj["foo"])
{
  // foo in set
}

This is basically how HashSet works in Java, assuming the JavaScript object is implemented as a hashtable (which is typical).