Check out example codes for "TYPESCript props class component". It will help you in understanding the concepts better.

Code Example 1

class Test extends Component<PropsType,StateType> {
  constructor(props : PropsType){
    	super(props)
  }
  
  render(){
   	console.log(this.props) 
    return (
     	<p>this.props.whatever</p> 
    )
  }
  
};

Code Example 2

interface IProps {
}

interface IState {
  playOrPause?: string;
}

class Player extends React.Component<IProps, IState> {
  // ------------------------------------------^
  constructor(props: IProps) {
    super(props);

    this.state = {
      playOrPause: 'Play'
    };
  }

  render() {
    return(
      <div>
        <button
          ref={playPause => this.playPause = playPause}
          title={this.state.playOrPause} // in this line I get an error
        >
          Play
        </button>
      </div>
    );
  }
}

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