CODEWITHSUNDEEP
javascriptnode.jsglobal-variables
Hydrothermal
Hydrothermal

Reputation: 5081

How can I dynamically access a global variable in Node?

In browser-based JavaScript, you can do something like this:

var foo = "foo";

(function() {
    var foo = "bar";

    console.log(foo);
    // => "bar"

    console.log(window["foo"]);
    // => "foo"
})();

Is there any way to do something similar in Node, which lacks a window object?

Upvotes: 3

Views: 2724

Answers (2)

Peter Olson
Peter Olson

Reputation: 143017

If you want an environment agnostic approach, for example, when writing code to work on both the browser and Node.js, you can do something like this in global code at the top of your JavaScript file:

var globalObject = typeof global === "undefined" ? this : global;

and then use globalObject similar to how you would window in the browser context and as you would use global in the Node.js context.

Note that you must declare a variable without var for it to be part of the global object in Node.js.

Upvotes: 1

Mritunjay
Mritunjay

Reputation: 25882

You can access global variables using global keyword in nodejs.

Note:- There is one rule in nodejs only those variables willl be global variables which dose not have declared using var.

Like if you have declareation like bellow

foo = "sample"; //this you can access using global

But

var foo = "sample"; //this you cann't access using global.

The second one is not actually in global scope, it's local to that module.

From node global docs

In browsers, the top-level scope is the global scope. That means that in browsers if you're in the global scope var something will define a global variable. In Node this is different. The top-level scope is not the global scope; var something inside a Node module will be local to that module.

Upvotes: 1

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