About global variables in Node.js

Question

Node.js seems to use different rules to attach variables to the global object whether this is done in the REPL or in a script.

$ node
> var a         


        

Answer 1

There is no window in Node.js but there is another highest object called global.

Whatever you assign to global.something in one module is accessible from another module.

Example:

app.js

global.name = "myName"

now you can get the global.name from any module

myController.js

console.log(global.name);  // output: myName

anotherModule.js

console.log(global.name);  // output: myName

now when you declare a variable at one module var i=0; is it available from all module? NO !

Because all your project code is wrapped under a module, On REPL it doesn't. it's the highest level. That's why REPL variable becomes global.

so if you want to work with global, you have to use with the global prefix

global.a = 1;
console.log(global.a);