Fehlermeldung:
Uncaught TypeError: Cannot read properties of undefined (reading 'state')

    onClickEdit(event) {

        window.location.href = "/edit/" + this.state.idarticle;

    }

    //*arrow()-function to get id

    onClickEdit = (event) => {

        //alert('you clicked me');

        //event.preventDefault(); //stops a href=url

        window.location.href = "/edit/" + this.state.idarticle;

        //later:browserHistory.push('/');

    }

<div style={{ float: 'right' }}>

<button type="button" className="btn btn-primary" onClick={this.onClickEdit }>Edit</button>

                                </div>