Java Basics

1. Getting Started

In this section, you will get acquainted with Java, understand its peculiarities, and why I would recommend learning this particular programming language. You will write your first Java code and familiarize yourself with printing text to the console. Shall we begin?

Backend Development

Role of Java in the Backend

2. Basic Types, Operations

We have completed a theoretical course, and now the most interesting part begins. In this section, we will familiarize ourselves with the basics of coding, primitive data types, and operations on them. Now your code can perform mathematical tasks and evaluate conditions for further execution. Sounds interesting? Let's start getting acquainted.

Primitive Data Types

Primitive Types Challenge

Char and ASCII Table (bonus)

Mathematical Operations in Java

If-Else Statement

Switch-Case Statement

Weekday Switch Challenge

3. Loops

In this section, we will familiarize ourselves with various loops such as for, while, and do-while. Loops are essential to any programming language, as they allow us to efficiently iterate over a large amount of data and save significant time. Later on, you will use loops extensively in tasks like sorting, working with arrays, collections, and more. Well then, let's get started.

Introduction to Loops

While-Loop

Do-While Loop

For-Loop

Increment and Decrement

Infinite Loop (bonus)

Challenge: Factorial

4. Arrays

This section will cover arrays and how to use them correctly. We will learn how to group data into arrays and explore some methods for working with arrays. Arrays are essential to any programming language Java, so let's dive in.

What is Array?

Using Loops with Arrays

Index Out Of Bounds

Two-Dimentional Array

Iteration In Two-Dimensional Array

For-Each Loop

5. String

In this section, you will be introduced to a data type called String. Why is there a separate section in the course for this data type? String is a significant data type with many built-in methods and operations. In this course, you will learn about String and StringBuilder, explore their basic methods, and learn how to use strings effectively in Java. So, are you ready to get started?

What Is String?

Basic Methods In String Part 1

Basic Methods In String Part 2

B-Inclusion Filter Challenge

NullPointer Exception

StringBuilder

String Pool, Method Equals()

Summary

Increment and Decrement

Increment

The increment operator, denoted by "++", is used to increase the value of a variable by 1. It is commonly used in loops to control the iteration process. There are two ways to use the increment operator:

Post-increment (i++): The variable's value is incremented after it is used in the expression. For example:

Main.java

Pre-increment (++i): The variable's value is incremented before it is used in the expression. For example:

Main.java

Decrement

The decrement operator, denoted by "--," is used to decrease the value of a variable by 1. It follows the same rules as the increment operator and can be used in a similar way.

Here's an example of using increment and decrement in a for loop:

Main.java

In the first "for" loop, the variable "i" is initialized to "0," incremented by "1" after each iteration, and the loop executes until "i" is no longer less than "5." This will output the numbers from 0 to 4.

In the second "for" loop, the variable "j" is initialized to "5," decremented by "1" after each iteration, and the loop executes until "j" is no longer greater than "0." This will output the numbers from 5 to 1 in descending order.

Note
The increment (++) and decrement (--) operators are useful for controlling the flow and counting in loops. They provide a convenient way to manipulate variables within the loop's execution.

Assignment Operators

Java also allows you to simplify expressions using assignment operators. In general, if increment increases the value of a variable by 1, and decrement decreases it by 1, then with assignment operators, we can customize any operation. For example,

x = x + 2 equals to x+=2

You can also do it with any type of operation, even with multiplication and division:

x = x * 4 equals to x*=4;

Let's take a look at a real example of using an assignment operation in a for loop:

main.java

You can see in the code above how we increment the variable i by 10 with each iteration as long as i < 50.

This way, we can shorten and combine different operations while immediately assigning the result to a variable. Very useful!

1. What will be the output of the following code snippet?

2. What will be the output of the following code snippet?

Everything was clear?

Section 3. Chapter 5

Increment and Decrement

Increment

Post-increment (i++): The variable's value is incremented after it is used in the expression. For example:

Main.java

Pre-increment (++i): The variable's value is incremented before it is used in the expression. For example:

Main.java

Decrement

The decrement operator, denoted by "--," is used to decrease the value of a variable by 1. It follows the same rules as the increment operator and can be used in a similar way.

Here's an example of using increment and decrement in a for loop:

Main.java

Note
The increment (++) and decrement (--) operators are useful for controlling the flow and counting in loops. They provide a convenient way to manipulate variables within the loop's execution.

Assignment Operators

x = x + 2 equals to x+=2

You can also do it with any type of operation, even with multiplication and division:

x = x * 4 equals to x*=4;

Let's take a look at a real example of using an assignment operation in a for loop:

main.java

You can see in the code above how we increment the variable i by 10 with each iteration as long as i < 50.

This way, we can shorten and combine different operations while immediately assigning the result to a variable. Very useful!

1. What will be the output of the following code snippet?

2. What will be the output of the following code snippet?

Everything was clear?

Section 3. Chapter 5