Lessons

About Java

Java is the most popular programming language. Did you know that Java is the world's most popular programming language? According to the TIOBE ranking, the Java programming language is used by 17% of all programmers in the world. C++ comes in second with 15%. 20 years ago, when the Java language just appeared, the undisputed leader was...

Hello. If you are reading these lines, then, yes, you're in the right place: these are Java lessons. This training course is simply chock full of practice (1500+ practical tasks) and is designed for an adult audience.

CodeGym tasks and everything associated with them

We believe more than anyone in the power of online learning. Big desire + a goal + a clear plan = a future Java developer. That's why we created a massive course, stuffed with practice and concentrated theory. We came up with a motivational system as well as the ability to design your own individual training schedule. We introduced features that help users from different countries to communicate, help each other, and share practical experience. And then one day we thought, why not take this further?

Commands. A program is a set (list) of commands. First, the first command is executed, then the second, the third, and so on. When all the commands have been executed, the program ends. The specific commands that are allowed in the list depend on who is performing the command, i.e. what commands does the performer know or understand. You...

Parameters of the println() method. A method body consists of commands. You could even say that a method is a group of commands that has been given a name, i.e. the method name. Either perspective is accurate. There are different kinds of commands. The Java language has a command for every occasion.  Each command defines some specif...

To make it easier for you to solve tasks, we've written a special widget: WebIDE.

Variables and boxes. Variables are special things for storing data. Any data. All data in Java is stored using variables. One of the best ways to conceive of a variable is as a box. A completely ordinary box. For example, let's say that you write the number 13 on a piece of paper and put it...

Declaring variables. Let's take another look at how to create variables. Repetition is the mother of learning. To create (or declare) a variable, you need use the name of the variable's type. Examples: Command Explanation String s; A String variable named s is created. This variable can store text.

Two kinds of comments. We should add a few words to what was said above. In Java, you can write commands, but you can also add comments to those commands right in the code. The compiler completely ignores the comments. When the program is run, all the comments are omitted." Here's an example: public clas...

The String type. The String type is one of the most used types in Java. It very well may be the most used type. There's a reason why it is so popular: variables of this type let you store text — and who doesn't want to do that? Additionally, unlike the int and double types, you can call methods on objects of the String type, and these methods do...