This article will show you the most suitable solutions to fix “Cannot find name #” error in React Typescript. Check out the following information.
What does this error mean?
When working on a TypeScript project, we write JSX code in a file with the extension ‘.ts‘ instead of ‘.tsx‘, then the message error “Cannot find name #” will appear. Occasionally, errors can also occur because you have not fully installed all the ‘@types‘ packages for your project.
For instance, take a look at the following example of an error case:
export default function Home() {
return (
<div>
<h1>We are LearnShareIT</h1>
<p>Welcome to our website</p>
</div>
);
}
Error:
Solution for the “Cannot find name #” error in React Typescript
Using a file with the ‘.tsx’ extension
The first way you should try to fix this error is to use the extension ‘.jsx’ for all files containing the JSX code.
Continuing with the example above, you don’t need to change anything in your code but simply change the extension to ‘.jsx‘.
export default function Home() {
return (
<div>
<h1>We are LearnShareIT</h1>
<p>Welcome to our website</p>
</div>
);
}
In tsconfig.json, make sure the ‘jsx‘ option in the ‘compilerOptions‘ object is set to ‘react-jsx‘. To illustrate, it should look like this:
{
"compilerOptions": {
"jsx": "react-jsx",
//other options
}
}
After making changes, you should restart the IDE as well as the development server to keep the system updated with the latest changes, avoiding unexpected errors.
Now the problem seems to have been solved.
Installing all the necessary packages
Another cause of this error is that you have not installed all the necessary packages.
We recommend fully installing typings for the following packages: react, react-dom, node, jest, and typescript.
To do that, open the terminal in the root directory of your project and run the commands below:
::NPM
npm install --save-dev @types/react @types/react-dom @types/node @types/jest typescript
::YARN
yarn add @types/react @types/react-dom @types/node @types/jest typescript --dev
Please check your installation was successful by opening file ‘package.json‘ and checking if the installed packages are in the object ‘devDependencies‘:
{
"devDependencies": {
"@types/react": "^18.0.24",
"@types/react-dom": "^18.0.8",
"@types/jest": "^29.2.0",
"@types/node": "^18.11.7",
"typescript": "^4.8.4",
//other options
}
}
Summary
In conclusion, we have provided you with two methods for the “Cannot find name #” error in React Typescript through this post. We hope the information we provide is helpful to you. Thanks for reading the whole article.
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My name’s Christopher Gonzalez. I graduated from HUST two years ago, and my major is IT. So I’m here to assist you in learning programming languages. If you have any questions about Python, JavaScript, TypeScript, Node.js, React.js, let’s contact me. I will back you up.
Name of the university: HUST
Major: IT
Programming Languages: Python, JavaScript, TypeScript, Node.js, React.js