The Uncaught SyntaxError: Unexpected Token < in React is a common issue that developers may encounter while working on React applications. This error usually occurs when there is an issue with the configuration or the code. In this guide, we will understand the possible reasons for this error and provide step-by-step solutions to resolve it.
Table of Contents
- Solution 1: Check the Webpack Configuration
- Solution 2: Correct the Source Attribute in HTML
- Solution 3: Verify the Babel Configuration
- Solution 4: Confirm the Correct File Path
Possible Causes of Uncaught SyntaxError: Unexpected Token <
There could be multiple reasons for encountering the Uncaught SyntaxError: Unexpected Token < in React. Some of the possible causes are:
- Incorrect Webpack configuration
- Incorrect
srcattribute in HTML - Incorrect Babel configuration
- Incorrect file path
Solutions to Fix the Error
Solution 1: Check the Webpack Configuration
The first step is to check the Webpack configuration. Ensure that the entry point for your application is correctly specified in the configuration file. Here's an example of a basic Webpack configuration:
module.exports = {
entry: './src/index.js',
output: {
path: __dirname + '/public',
filename: 'bundle.js'
},
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader'
}
}
]
}
};
Ensure that the entry point is correctly specified as './src/index.js' or the appropriate entry point for your application.
Solution 2: Correct the Source Attribute in HTML
The second step is to ensure that the src attribute in your HTML file points to the correct bundled JavaScript file. For example:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>React App</title>
</head>
<body>
<div id="root"></div>
<script src="/bundle.js"></script>
</body>
</html>
Make sure the src attribute in the script tag is set to /bundle.js or the appropriate bundled JavaScript file path.
Solution 3: Verify the Babel Configuration
The third step is to check if your Babel configuration is correct. In your .babelrc file, ensure that the following presets are specified:
{
"presets": [
"@babel/preset-env",
"@babel/preset-react"
]
}
These presets ensure that your code is transpiled correctly for the browser to understand.
Solution 4: Confirm the Correct File Path
Lastly, ensure that your file paths are correct. If you are using an incorrect file path, the browser may not be able to locate the file, resulting in the Uncaught SyntaxError.
FAQs
1. What is the Uncaught SyntaxError: Unexpected Token < in React?
The Uncaught SyntaxError: Unexpected Token < in React is a common error that occurs when there is an issue with the configuration or the code. It usually indicates that the browser is unable to understand some part of the code or configuration.
2. Can this error be caused by incorrect Webpack configuration?
Yes, incorrect Webpack configuration can cause this error. Make sure that the entry point for your application is correctly specified in the configuration file.
3. Can this error be caused by incorrect Babel configuration?
Yes, incorrect Babel configuration can cause this error. Ensure that the appropriate presets are specified in your .babelrc file.
4. How can I fix the error if it is caused by an incorrect file path?
To fix the error caused by an incorrect file path, ensure that your file paths are correct. If the browser is unable to locate the file due to an incorrect file path, it may result in the Uncaught SyntaxError.
5. Can this error be caused by the incorrect src attribute in the HTML file?
Yes, this error can be caused by the incorrect src attribute in the HTML file. Make sure that the src attribute in the script tag is set to the correct bundled JavaScript file path.