hugohenrique/Environment.js

## Environment.js
var Environment = function () {
  'use strict';

  function Environment() {
    this.variables = {};
  }

  Environment.prototype.exist = function (name) {
    return !!this.variables[name];
  };

  Environment.prototype.add = function (name, value) {
    if (!this.exist(name)) {
      this.variables[name] = [];
    }

    this.variables[name] = value;
  };

  Environment.prototype.get = function (name) {
    if (!this.exist(name)) {
      throw new Error('The variable name cannot be found');
    }

    return this.variables[name];
  };

  Environment.prototype.replace = function (name, value) {
    if (!this.exist(name)) {
      throw new Error('The variable name cannot be found');
    }

    if (this.variables[name] !== value) {
      this.variables[name] = value;
    }
  };

  Environment.prototype.isEmpty = function (name) {
    return this.get(name).length === 0;
  };

  return Environment;
};

## Example.html
<html>
  <head>
    <meta charset="utf-8">
  </head>

  <body>
    <script src="Environment.js"></script>
    <script>
      var env = new Environment();
      env.add('language', 'ptBR');
      env.add('websocket.url', 'ws://my.ip.server');

      var websocket = new WebSocket(env.get('websocket.url'));
    </script>
  </body>
</html>
	var Environment = function () {
	'use strict';

	function Environment() {
	this.variables = {};
	}

	Environment.prototype.exist = function (name) {
	return !!this.variables[name];
	};

	Environment.prototype.add = function (name, value) {
	if (!this.exist(name)) {
	this.variables[name] = [];
	}

	this.variables[name] = value;
	};

	Environment.prototype.get = function (name) {
	if (!this.exist(name)) {
	throw new Error('The variable name cannot be found');
	}

	return this.variables[name];
	};

	Environment.prototype.replace = function (name, value) {
	if (!this.exist(name)) {
	throw new Error('The variable name cannot be found');
	}

	if (this.variables[name] !== value) {
	this.variables[name] = value;
	}
	};

	Environment.prototype.isEmpty = function (name) {
	return this.get(name).length === 0;
	};

	return Environment;
	};
	<html>
	<head>
	<meta charset="utf-8">
	</head>

	<body>
	<script src="Environment.js"></script>
	<script>
	var env = new Environment();
	env.add('language', 'ptBR');
	env.add('websocket.url', 'ws://my.ip.server');

	var websocket = new WebSocket(env.get('websocket.url'));
	</script>
	</body>
	</html>