Welcome to Java programming! This guide covers the basics of Java syntax and programming concepts.
Here's the classic "Hello World" program in Java:
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}Java has several primitive data types:
public class DataTypes {
public static void main(String[] args) {
// Integer types
int age = 25;
long population = 7800000000L;
// Floating point types
double price = 19.99;
float temperature = 36.5f;
// Character and boolean
char grade = 'A';
boolean isActive = true;
// String (reference type)
String name = "John Doe";
System.out.println("Name: " + name);
System.out.println("Age: " + age);
System.out.println("Grade: " + grade);
}
}Object-oriented programming is fundamental to Java:
public class Robot {
private String name;
private int batteryLevel;
// Constructor
public Robot(String name) {
this.name = name;
this.batteryLevel = 100;
}
// Methods
public void move(String direction) {
if (batteryLevel > 0) {
System.out.println(name + " is moving " + direction);
batteryLevel -= 10;
} else {
System.out.println(name + " needs charging!");
}
}
public void charge() {
batteryLevel = 100;
System.out.println(name + " is fully charged!");
}
// Getters
public int getBatteryLevel() {
return batteryLevel;
}
}This covers the basics of Java programming!