Basic Methods In String Part 1

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

Basic Methods In String Part 1

How to Work with Strings Using Methods?

As mentioned earlier in the "Array" section, we won't delve into what methods are and how to create them. We will discuss this later in a separate course. For now, it will be sufficient for you to know that methods are invoked using a dot (.) after the String variable we created.

Let's take a look at several commonly used methods:

length(): Returns the length of the string;

Main.java

charAt(int index): Returns the character at the specified index in the string;

Main.java

substring(int beginIndex): Returns a new string that is a substring of the original string, starting from the specified index;

Main.java

substring(int beginIndex, int endIndex): Returns a new string that is a substring of the original string, starting from the beginIndex and ending at the endIndex-1;

Main.java

toLowerCase(): Converts the string to lowercase;

Main.java

toUpperCase(): Converts the string to uppercase;

Main.java

contains(CharSequence sequence): Checks if the string contains the specified sequence of characters;

Main.java

replace(char oldChar, char newChar): Replaces all occurrences of the specified oldChar with the newChar;

Main.java

toCharArray(): Converts the string to a character array.

Main.java

The list turned out to be quite extensive, so we'll continue exploring String methods in the next chapter.

In the following chapter, we will provide practical examples of using these methods.

Everything was clear?

Section 5. Chapter 2

Basic Methods In String Part 1

How to Work with Strings Using Methods?

Let's take a look at several commonly used methods:

length(): Returns the length of the string;

Main.java

charAt(int index): Returns the character at the specified index in the string;

Main.java

substring(int beginIndex): Returns a new string that is a substring of the original string, starting from the specified index;

Main.java

substring(int beginIndex, int endIndex): Returns a new string that is a substring of the original string, starting from the beginIndex and ending at the endIndex-1;

Main.java

toLowerCase(): Converts the string to lowercase;

Main.java

toUpperCase(): Converts the string to uppercase;

Main.java

contains(CharSequence sequence): Checks if the string contains the specified sequence of characters;

Main.java

replace(char oldChar, char newChar): Replaces all occurrences of the specified oldChar with the newChar;

Main.java

toCharArray(): Converts the string to a character array.

Main.java

The list turned out to be quite extensive, so we'll continue exploring String methods in the next chapter.

In the following chapter, we will provide practical examples of using these methods.

Everything was clear?

Section 5. Chapter 2