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 class in JavaScript ES6?
A). class ClassName { constructor() {} }
B). function ClassName() { constructor() {} }
C). class ClassName() { constructor {} }
D). function class ClassName { constructor() {} }
What will console.log(newCar.make); output if class Car { constructor(make) { this.make = make; }} var newCar = new Car('Honda');?
A). Honda
B). Car
C). Undefined
D). Error
How do you define a method inside a class in JavaScript ES6?
A). methodName() {}
B). this.methodName = function() {}
C). function methodName() {}
D). methodName: function() {}
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';
What is the correct way to create an object in JavaScript?
A). var obj = {};
B). var obj = [];
C). var obj = ();
D). var obj = {};
What is the purpose of the this keyword in a constructor function?
A). It refers to the new object being created.
B). It refers to the global object.
C). It refers to the current object.
D). It refers to the parent object.
What will console.log(car.make); output if var car = {make: 'Toyota', model: 'Corolla'};?
A). Toyota
B). Corolla
C). Undefined
D). Error
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 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: () {}