import React, { Component } from 'react' class Counter extends React.Component { constructor(){ super() this.state = { value: 0 }; } incrementar = () => { this.setState({value:this.state.value+1}) }; decrementar = () => { this.setState({value:this.state.value-1}) }; render() { return ( <div> <h2>{this.state.value}</h2> <button onClick={this.decrementar}>Decrementar</button> <button onClick={this.incrementar}>Incrementar</button> </div> ); } } export default function App() { return <Counter />; }