Node basics-Global

Global Object:

• Global: Always use VaR to define variables to avoid introducing global variables;
• Process: The content of all global execution contexts is in the Process object;

Module System:Three global variables

• Require (): If the module is not in node_modules, the relative path must be used for import;
• Exports: Some attributes can be defined on this object. APIs exposed using this object as a module;
• Module: exports is module. Exports. you can completely overwrite exports and change it to an exposed API;

Listener event:Eventemitter; comparison window. addeventlisten;

VaR eventemitter = require ('events '). eventemitter; // obtain the listener method corresponding to the import module; var A = new eventemitter; // create an object based on this method;. on ('event', function () {});/. once ('event', function () {}); // listens to related events on this object

 

Node basics-Global