So überprüfen Sie, ob das Objekt einen Schlüssel -JavaScript hat
myObj.hasOwnProperty('key') // it checks object for particular key and not on prototype
Proud Pony
myObj.hasOwnProperty('key') // it checks object for particular key and not on prototype if ('key' in myObj)"key" in obj // true, regardless of the actual valueObject.prototype.hasOwnProperty()Object.prototype.hasOwnProperty.call(object, key)console.log("key" in obj)