When an event handler uses this (juet like handleClick below uses this.setState), you have to bind the event handler with this>         
        
I used to do this kind of thing for state names. Depends on what you want, you can try this. So that, i don't have to bind the function again. Where you can get state name from e.target.name
class App extends React.Component {
  state = {
    change: ""
  };
  handleChange = e => {
    const { name, value } = e.target;
    this.setState({ [name]: value  })
  };
  render() {
    return (
      
    );
  }
}