What is the purpose of the initialize method in Ruby?

Vaibhav Kothia May 31, 2023 0 Comments

The initialize method is a special method in Ruby that is automatically called when an object is created. It can be used to set up or initialize any variables that the object will need when it is created.

For example, if you were creating a class to represent a Person, you might use the initialize method to set the person’s name and age:

class Person
def initialize(name, age)
@name = name
@age = age
end
end

person = Person.new(“John”, 30)
puts person.inspect #

What is the purpose of the super keyword in Ruby?

Vaibhav Kothia May 31, 2023 0 Comments

The super keyword in Ruby is used to call a method from a parent or superclass. This is useful when you want to override a method in a subclass and still access the original method.

For example, say you have a superclass called Animal and a subclass called Cat. The Animal class has a method called speak that prints out “Meow”.

class Animal
def speak
puts “Meow”
end
end

class Cat Purr
# => Meow

What is the purpose of the self keyword in Ruby?

Vaibhav Kothia May 31, 2023 0 Comments

The self keyword in Ruby refers to the current instance of the class. It is used to access instance variables and methods within the class.

For example:

class Person
attr_accessor :name

def initialize(name)
@name = name
end

def say_hello
puts “Hello, my name is #{self.name}”
end
end

person = Person.new(“John”)
person.say_hello

# Output:
# Hello, my name is John

What is the difference between a class and a module in Ruby?

Vaibhav Kothia May 31, 2023 0 Comments

A class is an object-oriented programming construct that is used to define a type of object. It defines both the data and the behavior of the objects of that type. Classes are the building blocks of object-oriented programming.

Example:

class Dog
attr_accessor :name, :breed
def initialize(name, breed)
@name = name
@breed = breed
end
end

A module is a collection of methods and constants that can be included in classes. It is used to provide a namespace and prevent name clashes between similarly named methods.

Example:

module Dog
def bark
puts “Woof!”
end
end

What is the purpose of the ‘this’ keyword?

Vaibhav Kothia May 30, 2023 0 Comments

The ‘this’ keyword is used to refer to the current object in a method or constructor. It can be used to access the object’s properties and methods.

For example,

class Car {
constructor(make, model, color) {
this.make = make;
this.model = model;
this.color = color;
}

getCarInfo() {
return `This car is a ${this.make} ${this.model} in the color ${this.color}.`;
}
}

const myCar = new Car(‘Honda’, ‘Civic’, ‘red’);
console.log(myCar.getCarInfo());

// Output: This car is a Honda Civic in the color red.

What is the difference between a class and a module?

Vaibhav Kothia May 26, 2023 0 Comments

A class is a blueprint for creating objects, while a module is a collection of methods and constants that can be used by other classes.

For example, a class might be used to create objects that represent a car, such as a Ford Mustang. The class would define the attributes of the car, such as the make, model, and color.

A module, on the other hand, might contain methods for calculating fuel efficiency or calculating the cost of repairs. These methods could be used by any class, not just the car class.

What is Ruby?

Vaibhav Kothia May 26, 2023 0 Comments

Ruby is an open-source, object-oriented programming language. It was created in the mid-1990s by Yukihiro Matsumoto in Japan. Ruby is used for building web applications, websites, and other software.

Example:

# Create a new class called “Person”
class Person

# Define an initialize method to set the name
def initialize(name)
@name = name
end

# Define a method to greet the person
def greet
puts “Hello, my name is #{@name}!”
end
end

# Create a new person object
person = Person.new(“John”)

# Call the greet method
person.greet

What is the difference between a category and a class extension?

Vaibhav Kothia May 26, 2023 0 Comments

A category is a way of adding additional methods to an existing class, without having to subclass it. For example, you could add a category to the NSString class to add a method that converts a string to a URL.

A class extension is a way of adding additional private methods and properties to an existing class. For example, you could add a class extension to the UIViewController class to add a private method that handles the loading of view data from a remote server.

What is the difference between a constructor and a method in Java?

Vaibhav Kothia May 26, 2023 0 Comments

A constructor is a special type of method that is used to create an instance of a class. It is called when an object of a class is created and has the same name as the class. A constructor does not have a return type and is used to initialize the state of an object.

Example:

public class Car {
private String make;
private String model;

// Constructor
public Car(String make, String model) {
this.make = make;
this.model = model;
}
}

A method is an ordinary subroutine that is used to perform a specific task. It is declared with a return type and a name, and can take arguments. It is called on an instance of a class and can return a value.

Example:

public class Car {
private String make;
private String model;

// Method
public String getMake() {
return make;
}
}

What is a class in Java?

Vaibhav Kothia May 26, 2023 0 Comments

A class in Java is a template that defines the properties and behaviors of an object. It is the basic building block of an object-oriented language.

For example, a class called “Car” might have properties such as make, model, color, and year. It could also have behaviors such as start, accelerate, brake, and turn. The class would define how these properties and behaviors are related.