Which of the following correctly creates an instance of a Car object using a constructor function?
A). var myCar = Car('Toyota', 'Corolla', 2020);
B). var myCar = new Car('Toyota', 'Corolla', 2020);
C). var myCar = create Car('Toyota', 'Corolla', 2020);
D). var myCar = construct Car('Toyota', 'Corolla', 2020);
What does Object.assign(target, ...sources) do?
A). Copies properties from sources to target
B). Compares properties between target and sources
C). Deletes properties in sources
D). Merges properties of sources into target and removes duplicates
Which of the following is the correct way to delete a property from an object?
A). remove object.property;
B). delete object.property;
C). delete object[property];
D). object.property = null;
How can you check if a property exists in an object?
A). 'property' in object
B). object.hasProperty('property')
C). object.contains('property')
D). object.includes('property')
Which method can be used to call a function defined within an object?
A). object.functionName();
B). object->functionName();
C). object::functionName();
D). object.callFunction('functionName');
What is encapsulation in the context of JavaScript objects?
A). Hiding the internal state and requiring all interaction to be performed through an object's methods
B). Extending one object from another
C). Creating a new object
D). Removing a property from an object
What does Object.keys(obj) return?
A). An array of the values of the object's properties
B). An array of the names of the object's properties
C). The first key of the object
D). The number of properties in the object
What will car['make'] return if var car = {make: 'Ford', model: 'Mustang'};?
A). Ford
B). Mustang
C). Undefined
D). Error
How do you add a new property to an existing object in JavaScript?
A). object.property = value;
B). object->property = value;
C). object:property = value;
D). object.addProperty('property', value);
What is the output of car.start() if var car = {start: function() {console.log('Car started');}};?
A). Car
B). started
C). Car started
D). Error