ES6 Imports: Curly Braces – When to Use Them and When Not To?

ES6 Curly Braces in Single Module Imports: When to Use Them

When importing a single module in ES6, it's important to understand the difference between default imports and named imports, which determine the use of curly braces.

Default Imports (Without Curly Braces)

Default imports are used when the exported module has a single default export value. This value is imported directly without curly braces, as seen in the given example:

import initialState from './todoInitialState';

In this case, the initialState.js module has a default export named initialState. This default export is then directly imported using import initialState from ....

Named Imports (With Curly Braces)

Named imports are used when the exported module contains named exports, which are specific exports with named identifiers. To import named exports, curly braces are used, as in:

import { A } from './A';

Here, the A module contains a named export called A, which is imported using curly braces.

When to Use Curly Braces

Curly braces are used when importing named exports, where specific named identifiers are exported from the module. In the given example, using curly braces to import initialState led to an error because initialState is a default export, not a named export.

When Not to Use Curly Braces

Curly braces are not used when importing default exports. Default exports have no specific identifiers and can be imported directly without curly braces, as seen in the example import initialState from ....

In summary, curly braces in ES6 module imports indicate that named exports are being imported. Default exports do not use curly braces and are imported directly by their default export name.

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