lwc get Exception

// js error
if(ex.hasOwnProperty('mesage')){

    this.message = ['JS',ex.maessage].join('¥r¥n');
}
// apex error
if(ex.hasOwnproperty('body')){
    const messegeObj = JSON.pares(ex.body.message);
    this.message = [messageObj,messageObj.stackTrace].join('¥r¥n');
}