React.createElement: type is invalid — expected a string

React is a popular JavaScript library for building user interfaces. One of the core methods in React is React.createElement, which is used to create React elements. However, sometimes you may encounter an error message like “React.createElement: type is invalid — expected a string”. This error typically occurs when the type parameter passed to React.createElement is not a valid string.

There are a few common reasons why you might encounter this error:

1. Incorrect Import

If you are using JSX syntax in your code, make sure you have imported React correctly. The React object is required to be in scope when using JSX. You can import React using the following code:

import React from 'react';

2. Missing or Incorrect Component Name

Another possible reason for this error is that you might be passing an incorrect or non-existent component name to React.createElement. Make sure that the component name you are passing is a valid string and matches the name of the component you are trying to create.

3. Using JSX Syntax without Babel

If you are using JSX syntax without transpiling it with Babel or a similar tool, you may encounter this error. JSX is not natively supported by browsers, so it needs to be transpiled into regular JavaScript. Make sure you have the necessary build tools set up to transpile JSX code.

4. Using a Function Component without Capitalizing the Name

If you are using a function component, make sure that the component name starts with a capital letter. React treats components starting with a lowercase letter as DOM tags. For example, if you have a component named myComponent, you should rename it to MyComponent.

Example Solutions

1. Correct Import


import React from 'react';


2. Correct Component Name


const MyComponent = () => {
return

;
};


3. Transpiling JSX

If you are using a build tool like Babel, make sure you have the necessary plugins installed and configured to transpile JSX code. Here is an example configuration for Babel:


{
"presets": ["@babel/preset-react"]
}


4. Capitalize Function Component Name


const MyComponent = () => {
return

;
};


By following these solutions, you should be able to resolve the “React.createElement: type is invalid — expected a string” error. Remember to double-check your code for any typos or mistakes that might be causing the issue.