JS Modules
- JS modules helps us in organizing the our scripts and writing multi file code .
What is a module?
A module is just a file. One script is one module. As simple as that.
Modules can load each other and use special directives export and import to interchange functionality, call functions of one module from another one:
export keyword labels variables and functions that should be accessible from outside the current module. - import allows the import of functionality from other modules.
Note : All code that is not exported in a module will be executed only once and further it's imports will shared with other files.
There’s a rule: top-level module code should be used for initialization, creation of module-specific internal data structures. If we need to make something callable multiple times – we should export it as a function, like we did with sayHi above.