How do you iterate over all properties of an object var person = {name: 'John', age: 30};?
A). for (var key in person)
B). for (var key of person)
C). forEach(key in person)
D). forEach(key of person)
How can you check if the age property exists in the person object?
A). 'age' in person
B). person.has('age')
C). person.contains('age')
D). person.hasOwnProperty('age')
What is the correct way to create an object in JavaScript?
A). var obj = {};
B). var obj = [];
C). var obj = ();
D). var obj = <>;
How do you define a constructor function for creating Car objects?
A). function Car(make, model) { this.make = make; this.model = model; }
B). Car(make, model) { this.make = make; this.model = model; }
C). var Car = function(make, model) { this.make = make; this.model = model; };
D). Car = function(make, model) { this.make = make; this.model = model; };
What does Object.keys(person) return if var person = {name: 'John', age: 30};?
A). ['name', 'age']
B). ['John', 30]
C). {'name', 'age'}
D). {'John', 30}
How do you define a method named greet in an object var person = {};?
A). person.greet = function() {};
B). person.greet: function() {};
C). person.greet = () {};
D). person.greet = function {};
How do you add a method to an object created with a constructor function?
A). this.methodName = function() {}
B). this.methodName: function() {}
C). this.methodName = () {}
D). this.methodName: () {}
How do you inherit properties and methods from another class in JavaScript ES6?
A). class SubClass extends SuperClass {}
B). class SubClass inherits SuperClass {}
C). class SubClass implements SuperClass {}
D). class SubClass super SuperClass {}
How can you delete the age property from the person object?
A). delete person.age;
B). remove person.age;
C). person.age = null;
D). person.age.delete;
How do you access the value of the name property in the object var person = {name: 'John', age: 30};?
A). person['name']
B). person.name
C). person->name
D). person::name