Borislav Hadzhiev
Sun Mar 06 2022·3 min read
Photo by Zachary Staines
Use named exports to export multiple variables in TypeScript, e.g.
export const A = 'a'
and export const B = 'b'
. The exported variables can be
imported by using a named import as import {A, B} from './another-file'
. You
can have as many named exports as necessary in a single file.
Here is an example of exporting multiple variables from a file called
another-file.ts
.
// 👇️ named export export const greeting = 'hello'; // 👇️ named export export const name = 'James';
Note that using export
on the same line as the variable's definition is the
same as exporting the variables as an object after they have been declared.
const greeting = 'hello'; const name = 'James' // 👇️ named exports (same as code snippet above) export {greeting, name};
Here is how we would import the variables in a file called index.ts
.
// 👇️ named import import { greeting, name } from './another-file'; console.log(greeting); // 👉️ "hello" console.log(name); // 👉️ "James"
Make sure to correct the path that points to the another-file
module if you
have to. The example above assumes that another-file.ts
and index.ts
are
located in the same directory.
For example, if you were importing from one directory up, you would do
import {greeting, name} from '../another-file'
.
TypeScript uses the concept of modules, in the same way that JavaScript does.
The example above uses named exports and named imports.
The main difference between named and default exports and imports is - you can have multiple named exports per file, but you can only have a single default export.
If you try to use multiple default exports in a single file, you would get an error.
const greeting = 'hello'; const name = 'James'; // ⛔️ Error: A module cannot // have multiple default exports.ts(2528) export default greeting; export default name;
IMPORTANT: If you are exporting a variable (or an arrow function) as a default export, you have to declare it on 1 line and export it on the next. You can't declare and default export a variable on the same line.
Having said that, you can use 1
default export and as many named exports as
you need in a single file.
Let's look at an example that exports multiple variables and uses both - default and named exports.
const greeting = 'hello'; // 👇️ named export export const name = 'James'; // 👇️ default export export default greeting;
And here is how you would import the two variables.
// 👇️ default and named imports import greeting, { name } from './another-file'; console.log(greeting); // 👉️ "hello" console.log(name); // 👉️ "James"
Notice that we didn't wrap the default import in curly braces.
We used a default import to import the greeting
variable and a named import to
import the name
variable.
You can only have a single default export per file, but you can have as many named exports as necessary.
You also don't have to think about which members are exported with a default or named export.