Create an Export Fallback with export default
The export declaration is used to export values from a JavaScript module. Exported values can then be imported into other programs with the import declaration or dynamic import.
Named exports are useful to export several values. During the import, one will be able to use the same name to refer to the corresponding value. Concerning the default export, there is only a single default export per module.
If you only need to export a single value from a module, or if the module represents a main feature of your application, use export default . If you need to export multiple values from a module, or if you want to organize your code into smaller, reusable components, use export with named exports.
var is the keyword that tells JavaScript you're declaring a variable. x is the name of that variable. = is the operator that tells JavaScript a value is coming up next.
The keyword let in Javascript is used to declare a variable that is block scoped in JavaScript. In JavaScript, the var keyword is typically used to declare a variable that is treated like any other variable, whereas variables declared using the let in JavaScript are block scoped.
Const is another keyword to declare a variable when you do not want to change the value of that variable for the whole program. The difference is just that var is for normal variable declaration whose value can be changed, whereas a variable value declared using const keyword cannot be changed.