JavaScript, wenn das Feld existiert
const hero = {
name: 'Batman'
};
hero.hasOwnProperty('name'); // => true
hero.hasOwnProperty('realName'); // => false
f0ru0l0rd
const hero = {
name: 'Batman'
};
hero.hasOwnProperty('name'); // => true
hero.hasOwnProperty('realName'); // => falseif ('field' in obj) {
}