JS Object-Oriented Programming: How to define constants?

JS has a keyword const, but the current browser does not seem to support, if you must define some constants, you can actually use closures, anonymous functions to implement the definition of constants.

For example:

var Class = (function () {  var upper_bound = 100;//defines the constant   var test={};  Defines a method for obtaining constants in a static method  Test.getupper_bound=function () {    return upper_bound;  }  return Test;}) ();

Usage:

  var k=class.getupper_bound ();                 Alert (k);//

In the case of multiple constants: You can also write this:

var Class = (function () {    //Private static attributes.  var constants = {//defines two constants    upper_bound:100,    lower_bound: -100  }  var test={};  Defines a static method  Test.getconstant=function (name) {//Get constant Method    return constants[name];  }  Return Test}) ();

Usage:

  var k=class.getconstant (' Upper_bound ');                 Alert (k);//