Default component property values

React lets you define default values for properties in a very declarative way. The default value is used if the parent does not pass a property.

Default values are returned by a method getDefaultProps, which is a member of the object passed to React.createClass. Here is some sample code:

var ComponentWithDefaultProps = React.createClass({
  getDefaultProps: function() {
    return {
      value: 'default value'
    };
  }
});