How to Define CSS Variables in Style Attribute in React and TypeScript

When working with React and TypeScript, you might come across the need to define CSS variables in the style attribute. CSS variables, also known as custom properties, allow you to store and reuse values throughout your stylesheets. In this blog post, we’ll explore how to define CSS variables in the style attribute in React and TypeScript.

Using Inline Styles

One way to define CSS variables in the style attribute is by using inline styles in React. Inline styles allow you to directly pass an object with style properties and values to the style attribute.

To define a CSS variable, you can use the var() function and provide a name for the variable. Then, you can assign a value to the variable using the -- syntax.

{`import React from 'react';

const MyComponent: React.FC = () => {
  const myVariable = 'red';

  return (
    

      Hello, CSS Variables!
    
  );
};

export default MyComponent;`}

In the example above, we define a CSS variable named --my-variable and assign the value 'red' to it. We then use the variable in the style object passed to the style attribute of the div element.

Using CSS-in-JS Libraries

If you prefer to use CSS-in-JS libraries like styled-components or Emotion, you can also define CSS variables in the style attribute using these libraries.

For example, with styled-components, you can define a CSS variable using the css template literal and the var() function.

{`import React from 'react';
import styled, { css } from 'styled-components';

const MyComponent = styled.div`
  --my-variable: red;
  ${({ myVariable }) => css`
    color: var(--my-variable);
  `}
`;

const App: React.FC = () => {
  return (
    
      Hello, CSS Variables!
    
  );
};

export default App;`}

In this example, we define a CSS variable named --my-variable with the value 'red' using the css template literal. We then use the variable in the color property of the styled component.

Conclusion

Defining CSS variables in the style attribute in React and TypeScript can be achieved using inline styles or CSS-in-JS libraries like styled-components. Inline styles allow you to directly pass an object with style properties and values to the style attribute, while CSS-in-JS libraries provide more advanced features for defining and using CSS variables.