default props react

// ES6 class
class CatComponent extends React.Component {    
  constructor(props) {}    
  render() {        
    return <div>{this.props.catName} Cat, 
      Eye Color: {this.props.eyeColor }, 
        Age: {this.props.age}</div>    
  }
}
CatComponent.defaultProps = {    
  catName: "Sandy",    
  eyeColor: "deepblue",    
  age: "120"
}import PropTypes from 'prop-types';

MyComponent.propTypes = {
  // You can declare that a prop is a specific JS type. By default, these
  // are all optional.
  optionalArray: PropTypes.array,
  optionalBool: PropTypes.bool,
  optionalFunc: PropTypes.func,
  optionalNumber: PropTypes.number,
  optionalObject: PropTypes.object,
  optionalString: PropTypes.string,
  optionalSymbol: PropTypes.symbol,

  // An object that could be one of many types
  optionalUnion: PropTypes.oneOfType([
    PropTypes.string,
    PropTypes.number,
    PropTypes.instanceOf(Message)
  ])
};Basic types:
- PropTypes.any: The prop can be of any data type
- PropTypes.bool: The prop should be a Boolean
- PropTypes.number: The prop should be a number
- PropTypes.string: The prop should be a string
- PropTypes.func: The prop should be a function
- PropTypes.array: The prop should be an array
- PropTypes.object: The prop should be an object
- PropTypes.symbol: The prop should be a symbol

Renderable types:
- PropTypes.node: The prop should be anything that can be rendered by React
  a number, string, element, or array (or fragment) containing these types
- PropTypes.element: The prop should be a React element

Instance types:
- PropTypes.instanceOf(class): The prop should be an instance of class

Multiple types:
- PropTypes.oneOf: The prop is limited to a specified set of values,
  treating it like an enum
- PropTypes.oneOfType: The prop should be one of a specified set of
  types, behaving like a union of types
  
Collection types:
- PropTypes.arrayOf: ensures that the prop is an array in which all 
  items match the specified type.
- PropTypes.objectOf: ensures that the prop is an object in which all 
  property values match the specified type.
- PropTypes.shape: ensures that the prop is an object that contains a set 
  of specified keys with values of the specified types.
- PropTypes.exact: use for strict (or exact) object matching