Q
What does Object.assign(target, ...sources) do?

Answer & Solution

Answer: Option A
Solution:
Object.assign(target, ...sources) copies properties from one or more source objects to a target object.
Related Questions on Average

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

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 do you define a constructor function for a Car object?

A). function Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

B). Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

C). function create Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

D). function construct Car(make, model, year) { this.make = make; this.model = model; this.year = year; }

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

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);

How can you iterate over all properties of an object?

A). for (var key of object)

B). for (var key in object)

C). for (var key with object)

D). for (var key over object)

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 create a method inside an object using an object literal?

A). methodName: function() {}

B). methodName = function() {}

C). methodName: () {}

D). methodName: method() {}

What will the following code output? console.log(car.make); if var car = {make: 'Honda', model: 'Civic'};

A). Honda

B). Civic

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);