How to enable the new Command Prompt features on Windows 10

Windows 10 is packed with lots of new and old features such as the beloved Start menu. One of my personal favorites is the new Command Prompt and its new features. For years, a lot of us have suffered the limitations of the command prompt such as not able to resize the window or simply paste data using Ctrl+V. These annoyances are now part of the past, and if you want to enjoy these new features too, you’ll need to follow the steps below.

Enable New Command Prompt

If you have upgraded to Windows 10 and you use the Command Prompt, make sure you follow these steps to enable the new Command Prompt features: How to enable the new Command Prompt features on Windows 10

Programming: A short history of computer languages

What is computer programming

The action or process of writing computer programs, that is the definition of computer programming. Unfortunately, that doesn’t tell us much.

In a more descriptive way, programming refers to the act of describing processes and procedures by developing a list of instructions and commands for a computer to execute. The type of objects that these instructions manipulate are numbers, words, sounds, images, and the like. The goal of manipulating these objects is to make a computer perform a task and get results which would be nearly impossible for a human being to perform in a timely and accurate manner. The tasks we instruct a computer to make are usually very repetitive and can involve millions of calculations in a short period of time. Programming: A short history of computer languages

An introduction to Single Responsibility principle (SRP)

This is the fifth and last article describing SOLID principles. This article is about the Single Responsibility principle. Hopefully it will help you understand what the principle is all about and why it’s important to keep it in mind when designing and writing your code.

What is the Single Responsibility principle?

Here is the definition from Wikipedia: The term was introduced by Robert C. Martin in an article by the same name as part of his Principles of Object Oriented Design, made popular by his book Agile Software Development, Principles, Patterns, and Practices. Martin described it as being based on the principle of cohesion, as described by Tom DeMarco in his book Structured Analysis and Systems Specification. An introduction to Single Responsibility principle (SRP)

An introduction to Open Closed principle (OCP)

This is the fourth article on SOLID principles which I started a few weeks ago. I hope this is useful for you and that it gives you a simple understanding of what the Open/Closed principle is all about.

What is the Open Closed principle?

Bertrand Meyer coined the term Open/Closed Principle which appeared in his book titled Object Oriented Software Construction in 1988. The principle reads “software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification“. An introduction to Open Closed principle (OCP)

An introduction to Liskov substitution principle (LSP)

This post is about the Liskov substitution principle (LSP). This is also the third of my posts about SOLID principles, following the posts I wrote about DI and ISP in the past few weeks.

What is Liskov substitution principle (LSP)?

This principle is based on Barbara Liskov’s definition of subtyping, commonly known as the Liskov substitution principle which states the following:

if S is a subtype of T, then objects of type T in a program may be replaced with objects of type S without altering any of the desirable properties of that program

or in my own words, in programming we cannot always represent our objects with real-life objects and so we need to make sure subtypes respect their parents. Using the illustration below, in order to follow this principle we need to make sure that the subtypes (duck, cuckoo, ostrich) respect the parent class (bird). This means that in our code, we should be able to replace bird with duck, cuckoo or ostrich.

Subtyping

The above illustration shows clearly how in object-oriented programming (OOP) we can reuse some of our classes by making use of inheritance. This also shows very simply how using a base/parent class can be very beneficial and it is a main part of OOP.

So what is the problem you might ask? what is the purpose of the Liskov substitution principle? the purpose of it is to help you avoid some problems when modeling your objects by making you aware of potential problems that aren’t so obvious when using inheritance at the time of development.

The idea is to keep the LSP in mind when developing our classes so a parent class like “bird” can point to any of its child class objects i.e. “duck”, “cuckoo” or “ostrich” during runtime without any issues.

A classic example of LSP violation

One of the most classic examples of LSP violation is the use of a Rectangle class as the parent of a Square class. At first it seems this is the right thing to do as in Mathematics a square is a rectangle. However, in code this is not always true and this is what I meant when I wrote above that you cannot model your objects in code as you would do in the real world.

Below is an example of how in code, something like deriving a class of type Square from a Rectangle class might seem ideal…

public class Rectangle
 {
    public double Height { get; set; }
    public double Width { get; set; }
 }

 public class Square : Rectangle
 {
    public Square CreateSquare(double w)
    {
       var newSquare = new Square
       {
          Height = w, Width = w
       };
       return newSquare;
    }
 }

The example above looks fine, you can call the method CreateSquare by passing a value which is then assigned to both the height and width values of the object, this results in a proper formed square where all sides are equal. The problem arises when you define a rectangle where the height and width have different values, if you then try to substitute that object using a Square object… you will get unexpected results as the Square object expects its height and width properties to have the same value all the time.

However, the Liskov substitution principle says that you should be able to substitute any of the child classes for its base class and the example of the rectangle/square clearly breaks that rule.

The Liskov Susbtitution Principle (LSP) is one of the SOLID principles which can help you during software development to avoid common mistakes that are hard to notice if you are not thinking about them when using inheritance and modeling your classes/objects.

Happy coding!