StorePlay.js

import React from "react";

class StorePlay extends React.Component {
  state = {
    count : 0,
  };

  componentDidMount() {

  }

  render() {
    return (
      <div>
        <button onClick={() => this.setState({ count : this.state.count+1})}>
          INCREMENT
        </button>
        <button onClick={() => this.setState({ count : this.state.count-1})}>
          DECREMENT
        </button>

        <h2>Count</h2>
        <div>{this.state.count}</div>

      </div>
    );
  }
}

export default StorePlay;