Q
How can you iterate over all properties of an object?

Answer & Solution

Answer: Option B
Solution:
The for...in loop iterates over all enumerable properties of an object.
Related Questions on Average

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

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 the purpose of the this keyword in an object method?

A). It refers to the global object.

B). It refers to the current object.

C). It refers to the parent object.

D). It refers to the previous 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

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

How do you define a method in a constructor function?

A). this.methodName = function() {}

B). this.methodName: function() {}

C). this.methodName = () {}

D). this.methodName: () {}

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 is the output of car.start() if var car = {start: function() {console.log('Car started');}};?

A). Car

B). started

C). Car started

D). Error

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; }