syntaxerror: unexpected token 'export'

3 min read 07-12-2024

SyntaxError: Unexpected Token 'export' – Decoding the JavaScript Error

The dreaded "SyntaxError: Unexpected token 'export'" in JavaScript often leaves developers scratching their heads. This error signifies a problem with how you're using the export keyword, a fundamental part of JavaScript modules for sharing code between files. This article will dissect the common causes of this error and provide solutions to get your code running smoothly.

Understanding JavaScript Modules and `export`

Before diving into the solutions, let's quickly review JavaScript modules. Modern JavaScript allows you to break down your code into manageable modules, enhancing organization and reusability. The export keyword is crucial for this; it allows you to make functions, variables, or classes available for use in other modules.

For example:

// myModule.js
export function greet(name) {
  console.log(`Hello, ${name}!`);
}

export const message = "This is a module.";

In this example, both the greet function and the message variable are exported, making them accessible from other files.

Common Causes of "SyntaxError: Unexpected token 'export'"

This error typically arises from one of the following issues:

1. Incorrect Environment:

Missing Module Support: The most frequent cause is attempting to use export in an environment that doesn't support ES modules (ECMAScript modules). Older browsers or JavaScript environments might not understand the export keyword. You'll need a bundler (like Webpack, Parcel, Rollup, or esbuild) or a transpiler (like Babel) to convert your ES modules into code compatible with older environments. Modern browsers generally have good support, but older versions might still pose a problem.
Incorrect File Type: Ensure your JavaScript file has the correct extension (.js). Some older systems might have issues if you use a different extension.

2. Incorrect export Syntax:

Misplaced export Keyword: The export keyword must be placed correctly. It should precede the declaration of the item you're exporting. The following is incorrect:
```
function greet(name) {
  console.log(`Hello, ${name}!`);
}
export greet; // Incorrect placement
```
The correct syntax is:
```
export function greet(name) {
  console.log(`Hello, ${name}!`);
}
```

Incorrect export default Syntax: If you're exporting a single default item, the syntax is slightly different:

export default function greet(name) {
  console.log(`Hello, ${name}!`);
}

// or

const message = "Hello, world!";
export default message;

3. Mixing Module Systems:

Conflicting Module Systems: You might unintentionally be mixing CommonJS modules (using module.exports or exports) with ES modules (export). Choose one system and stick with it within a single file. Mixing them will often lead to this error.

4. Typos and Syntax Errors:

Simple Errors: Double-check for typos in the export keyword itself or any surrounding code. Even a small mistake can cause this error. Look carefully at your semicolons, brackets, and other punctuation.

Troubleshooting Steps

Check Your Environment: Verify that your environment (browser, Node.js version, bundler/transpiler configuration) supports ES modules. Consult the documentation for your specific environment.
Examine Your export Statements: Carefully review each export statement for correct placement and syntax. Ensure that all exported items are properly declared.
Simplify Your Code: Temporarily comment out parts of your code to isolate the problematic section. This can help pinpoint the exact source of the error.
Use a Bundler or Transpiler: If you are using ES modules and targeting older browsers, a bundler or transpiler is almost always necessary to handle the export keyword correctly.
Check for Conflicting Module Systems: Make sure you aren't unintentionally mixing CommonJS and ES modules in the same file.
Consult the Browser Console: The browser's developer console often provides more detailed error messages that can help you pinpoint the problem's location within your code.

By carefully examining your code and following these troubleshooting steps, you should be able to resolve the "SyntaxError: Unexpected token 'export'" and get your JavaScript modules working correctly. Remember to check your environment's compatibility with ES modules—this is often the root cause.

syntaxerror: unexpected token 'export'