Java 8 Programming Tutorial for Beginners: Free Download140

Introduction

Java 8 is a major release of the Java programming language that introduced significant new features and enhancements. This tutorial is designed for beginners who want to learn the basics of Java 8 programming. We will cover the following topics:
Installing Java 8
Creating a Java 8 project
Writing your first Java 8 program
Data types and variables
Operators and expressions
Control flow
Methods
Classes and objects
Inheritance
Polymorphism
Exceptions
Collections
Lambda expressions
Stream API

Installing Java 8

To install Java 8, visit the Oracle website and download the Java Development Kit (JDK) for your operating system. Once you have downloaded the JDK, follow the instructions to install it.

Creating a Java 8 Project

To create a Java 8 project, open your preferred integrated development environment (IDE) and create a new project. In the project settings, select Java 8 as the target version.

Writing Your First Java 8 Program

Here is a simple Java 8 program that prints "Hello, world!" to the console:```java
public class HelloWorld {
public static void main(String[] args) {
("Hello, world!");
}
}
```

To run this program, open a command prompt, navigate to the directory where the program is saved, and type the following command:```
javac
```

This will compile the program. To run the compiled program, type the following command:```
java HelloWorld
```

This will run the program and print "Hello, world!" to the console.

Data Types and Variables

Data types define the type of data that a variable can hold. Java 8 supports the following primitive data types:
byte
short
int
long
float
double
boolean
char

Variables are used to store data in a computer program. To declare a variable, you must specify the data type of the variable and the name of the variable. For example, the following code declares a variable named `myAge` that can hold an integer value:```java
int myAge;
```

You can assign a value to a variable using the assignment operator (=). For example, the following code assigns the value 25 to the variable `myAge`:```java
myAge = 25;
```

Operators and Expressions

Operators are used to perform operations on variables and values. Java 8 supports a wide range of operators, including arithmetic operators, comparison operators, and logical operators.

Expressions are combinations of variables, operators, and values that evaluate to a single value. For example, the following expression evaluates to the sum of the variables `a` and `b`:```java
a + b
```

Control Flow

Control flow statements are used to control the flow of execution in a program. Java 8 supports the following control flow statements:
if statements
switch statements
loops
try-catch statements

The following code shows an example of an if statement:```java
if (a > b) {
// Do something
}
```

The following code shows an example of a loop:```java
for (int i = 0; i < 10; i++) {
// Do something
}
```

Methods

Methods are used to group related code into reusable blocks. Methods can be defined with or without parameters. The following code shows an example of a method that takes two integer parameters and returns their sum:```java
public int sum(int a, int b) {
return a + b;
}
```

To call a method, you simply specify the name of the method and the arguments that you want to pass to the method. For example, the following code calls the `sum` method and prints the result to the console:```java
(sum(1, 2));
```

Classes and Objects

Classes are used to create objects. Objects are instances of classes that contain data and methods. The following code shows an example of a class that defines a `Person` object:```java
public class Person {
private String name;
private int age;
public Person(String name, int age) {
= name;
= age;
}
public String getName() {
return name;
}
public void setName(String name) {
= name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
= age;
}
}
```

To create an object, you use the `new` keyword. The following code shows an example of how to create a `Person` object:```java
Person person = new Person("John", 30);
```

Once you have created an object, you can access its data and methods using the dot operator. For example, the following code retrieves the name of the `person` object:```java
String name = ();
```

Inheritance

Inheritance is a mechanism that allows a class to inherit the properties and methods of another class. The class that inherits the properties and methods is called the subclass, and the class that is inherited from is called the superclass. The following code shows an example of a subclass that inherits from the `Person` class:```java
public class Employee extends Person {
private int salary;
public Employee(String name, int age, int salary) {
super(name, age);
= salary;
}
public int getSalary() {
return salary;
}
public void setSalary(int salary) {
= salary;
}
}
```

The `Employee` class inherits all of the properties and methods of the `Person` class. In addition, the `Employee` class defines a new property called `salary`. The following code shows an example of how to create an `Employee` object:```java
Employee employee = new Employee("John", 30, 50000);
```

Once you have created an `Employee` object, you can access its properties and methods using the dot operator. For example, the following code retrieves the salary of the `employee` object:```java
int salary = ();
```

Polymorphism

Polymorphism is a mechanism that allows objects of different classes to be treated as objects of a common superclass. For example, the following code shows an example of how to create an array of `Person` objects that contains both `Person` objects and `Employee` objects:```java
Person[] people = {new Person("John", 30), new Employee("John", 30, 50000)};
```

The following code shows an example of how to iterate over the `people` array and print the name of each person:```java
for (Person person : people) {
(());
}
```

Even though the `people` array contains both `Person` objects and `Employee` objects, the `for` loop will print the name of each person because the `getName` method is defined in the `Person` class and is inherited by the `Employee` class.

Exceptions

Exceptions are objects that represent errors that occur during the execution of a program. Java 8 supports a wide range of exceptions, including `NullPointerException`, `IndexOutOfBoundsException`, and `ArithmeticException`. The following code shows an example of how to handle an exception:```java
try {
// Code that may throw an exception
} catch (Exception e) {
// Code to handle the exception
}
```

The `try` block contains the code that may throw an exception. The `catch` block contains the code

2025-01-05

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