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Hello! Let's recall our school biology course. No, not about pistils and stamens. And not about the reproduction of earthworms. But about the fact that all living beings are usually divided into various species. Birds, fish, the neighbor upstairs drilling at 6 in the morning, and so on. In general, people like to classify everything into species. If, for example, you enter a query about this in a search engine, there will be many options.

No, we haven't changed the topic of videos, and we still cheerfully talk about IT stuff. So, why are we talking about this? Everything will become clear now, don't worry. It doesn't matter in which programming language you write. In any case, any programming is working with information. Simply moving it from point A to point B or visualizing it. That's why the field is called IT, which stands for Information Technology. And if you try to apply this information,

Perceiving as a whole and dividing it into different types will make working with it much easier. For example, coming up with your own type for phrases or for numbers. Then you can work with each type differently and not make mistakes. It's great that this has already been invented and it's called typing in programming languages. Thanks to typing, the language understands how to work with each type of information.

Now do you understand what the introduction was about? Let's start with the fact that these types themselves depend on the programming language. In each one, they are named and can even work differently. And as you know, there are sooo many programming languages. But in most languages, some data types are named the same.

What we previously called a phrase is actually called strings. For example, the well-known phrase Hello, World!, with which programming begins - is a string.

Well, numbers are most often called numbers or integers. Sometimes they also distinguish numbers with a floating

Commas that are called floats or very large numbers called big integers. For truth or falsehood, they also came up with their own data type and called it boolean, in honor of the mathematician George Boole, who invented Boolean algebra. By the way, this type of data can only have two values: true and false - in other words, yes and no, true and false, or 1 and 0. There are even data types that store other data types. For example, arrays. No, they are not massive, it's just that there is an English word array, and that's how it's translated. In short, no matter what data types there are, it's also important to understand that each language can work with these types differently. But most of the time, everything is logical. If it's a number, you can add it to another number; if it's a string, you can calculate its length, and so on. Programming languages, in terms of typing, can be divided into two types - static and dynamic. The typing in them can also be divided into two types - strong and weak. And they can also be divided into

Languages with explicit and implicit typing

Alright, let's delve into this in more detail, as it sounds a bit confusing at the moment.

So, what are languages with static typing? These are programming languages where the types of information, that is, variables, in our code are defined before the program is even executed. That is, during the so-called compilation stage when all our source code is just translated into binary. If there are any issues with the types, the file won't compile. For example, these are C, Java, or C#.

And what about dynamic languages? These are languages where types are determined after the program is launched. That is, during its execution, when we reach the part in the code where this type is encountered. If statically typed languages are mostly compiled, meaning they are first fully translated into binary code, and then this binary code is executed. So, dynamic languages are mostly interpreted, which means the entire code is executed.

and is translated in real-time. For example, these are languages like JavaScript, PHP, Python, and Ruby. Let's take a look at this picture as an example. Here, two languages with similar names are clearly compared, but in reality, they are completely different. In Java, types for variables are immediately specified, meaning boxes with names for storing information that we can reuse later. Notice that we cannot change the recorded data type to another later on. In JavaScript, on the other hand, we do not specify anything and can easily change types. Now, let's move on to strong and weak typing. With strong, or as it is also called, strict typing, we cannot mix data types. For example, applying actions strictly for strings to numbers. However, with weak typing, the interpreter will automatically determine which data type is best to use. Strong typing is found in languages like Java, Python, Haskell, and Lisp, while weak typing is present in JavaScript, PHP, and Basic. Even if you don't know JavaScript, you have probably seen memes dedicated to its weak typing. Yes, there the interpreter, when adding a number and a string,

It will convert a number to a string and concatenate them. 
It's not that bad. Rather, it is related to the field where JavaScript is used, and there it's normal. 
But we're not saying you should ignore it. You need to be able to use such a feature carefully and know how the language will behave in one case or another.
Now, some Python would have long ago kicked our butts for such gypsy tricks.
For example, we created a function that simply adds two numbers. And then we told it to add a number to a string. And predictably, we got an error indicating that there was a data type error trying to add a number and a string.
Well, and the last two types - explicit and implicit typing. With explicit typing, you always need to strictly specify the type of the element. Look at the code written in C. It doesn't matter what it does, just pay attention to the lines where char and int are written.
We have clearly defined data types for each variable. Here we clearly see,

What about the variables info, dept, and emp on the left, the data types char and int are specified, meaning a string and a number. Also, if something goes wrong, we will find out before running the program. Now let's look at the code in Python. Here we have variables best_school, subscribe, and count_subscribes. Importantly, there are no explicit data type declarations in it. And that's the whole point. We don't need to specify anything for the variables. The compiler or interpreter automatically selects the necessary type based on the value of the variable you specified after the equal sign. Let's sum up all these facts and find out that Python is a dynamically typed language with strong implicit typing. And if at this point you also got inspired by the idea of typing and can't wait to determine the variable types and write your first beautiful typed code, come to our academy where we will teach you about scripting types. Seriously - there is a programming language called TypeScript that extends the capabilities of JavaScript. So if you are also annoyed that JS doesn't support strict typing,

Sign up for an introductory lesson via the link in the description and acquire a cool new skill! What does this division give? Probably, one language is cooler than another? If you visit forums for programmers, you will see a huge number of debates about which programming language is cooler. Often citing as an example that their language has cooler typing and in general, Python is... Well, okay, it's obvious that one programming language cannot be cooler than another. Each is simply used for its own tasks. Roughly speaking, if you need speed, security, and efficiency, then it's about languages with strict and static typing. And if you need to quickly and cheaply create a project, and then easily improve it, then a dynamic language is best suited. By the way, here's another cool fact. Sooner or later, you will run out of the types that are initially in the language. That's why in many programming languages, there is the possibility.

Creating your own data types.
To do this, objects are created. For example, you can create a data type Pizza and specify that the pizza has the operation eat. But this is already the topic of object-oriented programming.
It turns out that without data typing, the language would not understand how to work with certain types of information. It also provides additional security and clarity of the code.
In the end, a question arises. Are there programming languages without types? Write in the comments.
And as always, don't forget to give a like to this video, subscribe to this channel and Telegram channel, and of course, tell your friends and colleagues about us.
Bye!

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