Let's say, when your application starts, you are checking the connection to the database and/or doing some other operations which are in different files and you want to inform your app.js file about the connection or pass the information regarding certain operation in multiple files.
You can send an event across the app and wherever you are listening for that event, you can then perform some other operation like retry if db connection fails.
This is useful for communicating between multiple files, passing data between two js files etc.
Let's say, when your application starts, you are checking the connection to the database and/or doing some other operations which are in different files and you want to inform your app.js file about the connection or pass the information regarding certain operation in multiple files.
You can send an event across the app and wherever you are listening for that event, you can then perform some other operation like retry if db connection fails.
This is useful for communicating between multiple files, passing data between two js files etc.
Do you have any example Express project using event emitter?
this is effectively what socket.io does.