ES6: 25 Create an Export Fallback with export default

In the export lesson, you learned about the syntax referred to as a named export. This allowed you to make multiple functions and variables available for use in other files. There is another export syntax you need to know, known as export default. Usually you will use this syntax if only one value is being exported from a file. It is also used to create a fallback value for a file or module. Here is a quick example of export default:
export default function add(x,y) {
return x + y;
}
Note: Sinceexport default is used to declare a fallback value for a module or file, you can only have one value be a default export in each module or file. Additionally, you cannot use export default with var, let, or const

ES6: Import a Default Export

to import a default export, you need to use a different import syntax.
In the following example, we have a function, add, that is the default export of a file, "math_functions". Here is how to import it:
import add from "math_functions"; add(5,4); //Will return 9
The syntax differs in one key place - the imported value, add, is not surrounded by curly braces, {}. Unlike exported values, the primary method of importing a default export is to simply write the value's name after import.

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