Javascript Classes MCQ - Quiz

In object-oriented programming, a class is a template for creating objects.
An object is an instance of a class, and it has the same behavior as defined by the class.
The class defines the properties and methods that the object will have, and the object is created based on that template.
All objects of the same class have the same behavior, but they can have different property values.
For example, you could have a class called "Dog" that defines the behavior of a dog, such as barking and wagging its tail.
You could then create multiple objects of the "Dog" class, each representing a different individual dog with its own unique characteristics, such as breed and name.

In JavaScript, inheritance is implemented using prototypes, which are objects that serve as templates for creating other objects. There is no built-in inherit() function in JavaScript that allows one class to inherit from another, but you can achieve inheritance by setting up the prototype chain correctly.

To inherit from a superclass in JavaScript, you can use the Object.create() method to create a new object that has the superclass as its prototype. The new object will then inherit all of the properties and methods of the superclass.

For example:

function A() {
// Properties and methods of class A
}

A.prototype.sayHello = function() {
console.log('Hello from A');
}

function B() {
// Properties and methods of class B
}

// Set up inheritance
B.prototype = Object.create(A.prototype);

const b = new B();
b.sayHello(); // Output: "Hello from A"


Here, the B class is defined as a constructor function. The B prototype is then set to a new object that has the A prototype as its prototype using the Object.create() method.
This causes the B prototype to inherit all of the properties and methods of the A prototype, including the sayHello method. When we create a new B object using the new keyword, the object inherits the sayHello method from the B prototype, which in turn inherited it from the A prototype.

The instanceof operator is a JavaScript operator that is used to check if an object is an instance of a particular class or constructor function. It returns a boolean value indicating whether the object is an instance of the class or not.
The instanceof operator is written with the syntax object instanceof Class, where object is the object to be checked and Class is the constructor function or class to check against.
For example:
function A() {
// Properties and methods of class A
}

function B() {
// Properties and methods of class B
}

const a = new A();
console.log(a instanceof A); // Output: true
console.log(a instanceof B); // Output: false

const b = new B();
console.log(b instanceof A); // Output: false
console.log(b instanceof B); // Output: true

Here, we define two classes, A and B, and create two objects, a and b, using the new keyword. The instanceof operator is used to check if the objects are instances of the respective classes.
The first object, a, is an instance of A but not B, so the first two instanceof checks return true and false, respectively. The second object, b, is an instance of B but not A, so the last two instanceof checks return false and true, respectively.
The instanceof operator is useful for determining the type of an object at runtime and for implementing type checking in JavaScript programs.

The Object.defineProperty() method is used to define a new property on an object, or to modify an existing property on an object. It returns the object. Both Object.defineProperty() and Object.defineProperties() can be used to define new properties on an object.

The Object.defineProperties() method is a predefined function in the object library of JavaScript that is used to define new properties or modify existing properties on an object. It returns the object.
The Object.defineProperties() method takes an object as its first argument and a property descriptor object as its second argument. The property descriptor object can specify the characteristics of one or more properties to be added to or modified on the object.

A regular expression is a pattern of characters that is used to match character combinations in strings. In JavaScript, regular expressions are represented using the RegExp class. The RegExp class provides methods for working with regular expressions, such as test(), exec(), and match().

Both strings and the RegExp class have methods that use regular expressions. For example, the String.prototype.match() method returns an array of strings that match a given regular expression, and the String.prototype.replace() method replaces substrings that match a given regular expression with a replacement string.

Regular expressions are a powerful tool for pattern matching and string manipulation in JavaScript. They are often used to validate user input, search and replace text, and extract data from strings.

The Object.prototype.constructor property specifies the function that creates the object prototype. It is a property of the Object.prototype object, which is the prototype of all objects in JavaScript.

In the code snippet you provided, the constructor property is being used to return a complex number that is the complex conjugate of the current complex number. A complex conjugate is a mathematical operation that negates the imaginary part of a complex number.

Whether or not classes defined by the host environment (such as web browsers) can be augmented using Object.prototype depends on the implementation. In some cases, it may be possible to add methods to the prototype of a class and have those methods be inherited by objects that represent instances of the class.
For example, in many web browsers, it is possible to add methods to HTMLElement.prototype and have those methods be inherited by the objects that represent HTML tags in the current document.

The reload() method is a method of the Location object in JavaScript, which is used to reload the current page from the server. It can be called using the location.reload() notation.

Modules are generally designed to run in an unmodified (or almost unmodified) environment, and should minimize the number of global symbols they define, with the goal of having no module define more than one.