Props in React are like function arguments. You can use props to send data to a component.
Like default values for function arguments, props also have default values.
defaultProps
can be defined as a property on the component class itself to set the default props for the class.
defaultProps
is used forundefined
props, not fornull
props.
For example, let’s create a CustomButton
class in React that takes color
as a prop.
To set a default value for the color
prop, use the defaultProps
property of CustomButton
to set the default value of color
to blue
.
Notice that whenever you don’t pass the color
prop to CustomButton
, it will fall back to the blue
default prop value.
import React from 'react'; require('./style.css'); import ReactDOM from 'react-dom'; import App from './app.js'; ReactDOM.render( <App />, document.getElementById('root') );