ここを参考に
ohs30359.hatenablog.com
class Child extends React.Component { handleClick = () => { this.props.callback({'value':'mystr'}); } render() { return ( <button onClick={this.handleClick}>Click</button> ) } } class Parent extends React.Component { constructor(props){ super(props); this.state = { value: '', } } myFunc(message){ const result = message.value; alert(result); } render() { return ( <Child callback={this.myFunc}/> ) } } ReactDOM.render( <Parent/>, document.getElementById('container') );