about react and setsate

Hello master, I understand it well

class App extends Component {
  constructor(props) {
    super(props);
    this.state = {
      personas: [
        { id: 1, nombre: "Adolfo" },
        { id: 2, nombre: "Juan" }
      ]
    }
  }
  componentDidMount() {
    let personas = this.state.personas
    personas.forEach(item => {
      if (item.id === 2) item.nombre = "Jose"
      return item
    })
    this.setState({ personas })
  }
  render() {
    console.log(this.state.personas)
    return (
      <div className="App">
        <header className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h1 className="App-title">Welcome to React</h1>
        </header>
        <div className="App-intro">
          { 
            this.state.personas 
            ? this.state.personas.map((item, index) => {
              return <p key={index}>
                {this.state.personas[index].id} - {this.state.personas[index].nombre}
              </p>         
            })
            : ''
          }
        </div>
      </div>
    );
  }
}

QUESTION: I WANT TO DO IT FROM AN OWN FUNCTION AND WITH A SINGLE PROPERTY AND IT DOES NOT COME OUT AND BRINGS ME LIKE THIS

 ver(e){

        let enviado = this.state.enviado;
        enviado=e;
        this.setState({enviado});
        alert(this.state.enviado);


    }

BUT IT CONTINUES ME SHOWING THE PREVIOUS STATE THAT IS EMPTY