Javascript: Server sided dynamic variable names

Generally you would do something like:

var myVariables = {};
var variableName = 'foo';

myVariables[variableName] = 42;
myVariables.foo // = 42

In node.js there is the global context, which is the equivalent of the window context in client-side js. Declaring a variable outside of any closure/function/module as you would in plain Javascript will make it reside in the global context, that is, as a property of global.

I understand from your question that you want something akin to the following:

var something = 42;
var varname = "something";
console.log(window[varname]);

This in node.js would become:

var something = 42;
var varname = "something";
console.log(global[varname]);