What is the 'global' object in NodeJS
I\'ve just seen a weird behaviour of the this keyword in NodeJS environment. I\'m listing them with code. I\'ve run this codes with NodeJS v6.x, wi
-
While in browsers the global scope is the
windowobject, in nodeJS the global scope of a module is the module itself, so when you define a variable in the global scope of your nodeJS module, it will be local to this module.You can read more about it in the NodeJS documentation where it says:
global
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.js this is different. The top-level scope is not the global scope; var something inside an Node.js module will be local to that module.
And in your code when you write:
console.log(this)in an empty js file(module) it will print an empty object{}referring to your empty module.console.log(this);inside a self invoking function,thiswill point to the global nodeJS scope object which contains all NodeJS common properties and methods such asrequire(),module,exports,console...console.log(this)with strict mode inside a self invoking function it will printundefinedas a self invoked function doesn't have a default local scope object in Strict mode.
加载中...
- 热议问题