How do you define a method inside a class in JavaScript ES6?
A). methodName() {}
B). this.methodName = function() {}
C). function methodName() {}
D). methodName: function() {}
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 add a new property gender with value male to the person object?
A). person.gender = 'male';
B). person.gender = male;
C). person.gender = ['male'];
D). person[gender] = 'male';
How do you call a method from a parent class in a subclass in JavaScript ES6?
A). super.methodName()
B). this.methodName()
C). parent.methodName()
D). base.methodName()
How do you define a class in JavaScript ES6?
A). class ClassName { constructor() {} }
B). function ClassName() { constructor() {} }
C). class ClassName() { constructor {} }
D). function class ClassName { constructor() {} }
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; };
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')
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
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 delete the age property from the person object?
A). delete person.age;
B). remove person.age;
C). person.age = null;
D). person.age.delete;