Java for Beginners: Your Complete Getting Started Guide for 2026

Why Java Still Matters in 2026

Java has been a top-tier programming language for over 25 years. It powers Android apps, enterprise backend systems, financial trading platforms, and services at Google, Amazon, Netflix, and most Fortune 500 companies.

Despite newer languages entering the market, Java's position remains strong for several reasons:

• Massive job market -- Java consistently ranks in the top 3 most in-demand languages
• Enterprise dominance -- banks, insurance companies, and large corporations run on Java
• Android development -- Java (alongside Kotlin) is still used for Android apps
• Mature ecosystem -- Spring Boot, Hibernate, and other frameworks have decades of refinement
• Performance -- the JVM (Java Virtual Machine) is highly optimized for long-running applications

If you are targeting enterprise software, Android development, or high-paying corporate roles, Java is an excellent choice.

Java vs Other Languages

If you are deciding between Java and other languages, here is how Java compares:

Java vs Python: Java is more verbose but enforces strict typing that catches bugs at compile time. Python is quicker for prototyping and data science. Java is better for large-scale enterprise applications.

Java vs JavaScript: Different domains. JavaScript dominates web development. Java dominates enterprise backend and Android. They share similar syntax (curly braces, semicolons) but are fundamentally different languages.

Java vs Go: Go is simpler and compiles faster, but Java has a much larger ecosystem and job market. Go is preferred for cloud infrastructure; Java for enterprise applications.

Your First Java Program

Every Java program starts with a class and a main method:

1public class HelloWorld {
2    public static void main(String[] args) {
3        System.out.println("Hello, World!");
4    }
5}

This is more verbose than Python's print("Hello, World!"), but every line has a purpose:

• public class HelloWorld -- defines a class (Java requires everything to live inside a class)
• public static void main(String[] args) -- the entry point that runs when you execute the program
• System.out.println() -- prints a line to the console

Variables and Data Types

Java is statically typed, meaning you must declare the type of every variable.

1// Primitive types
2int age = 25;
3double price = 19.99;
4boolean isActive = true;
5char grade = 'A';
6 
7// Reference types
8String name = "Alice";
9int[] numbers = {1, 2, 3, 4, 5};

Primitive Types

| Type | Description | Example | |------|-------------|---------| | int | Whole numbers | 42 | | double | Decimal numbers | 3.14 | | boolean | True or false | true | | char | Single character | 'A' | | long | Large whole numbers | 9999999999L | | float | Less precise decimals | 3.14f |

The String Class

Strings in Java are objects, not primitives:

1String greeting = "Hello";
2String name = "Alice";
3 
4// Concatenation
5String message = greeting + ", " + name + "!";
6 
7// String methods
8int length = name.length();           // 5
9String upper = name.toUpperCase();    // "ALICE"
10boolean starts = name.startsWith("A"); // true
11String sub = name.substring(0, 3);    // "Ali"

Control Flow

If-Else

1int score = 85;
2 
3if (score >= 90) {
4    System.out.println("A");
5} else if (score >= 80) {
6    System.out.println("B");
7} else if (score >= 70) {
8    System.out.println("C");
9} else {
10    System.out.println("F");
11}

For Loops

1// Traditional for loop
2for (int i = 0; i < 5; i++) {
3    System.out.println(i);
4}
5 
6// Enhanced for loop (for-each)
7String[] fruits = {"apple", "banana", "orange"};
8for (String fruit : fruits) {
9    System.out.println(fruit);
10}

While Loop

1int count = 0;
2while (count < 5) {
3    System.out.println(count);
4    count++;
5}

Methods

Methods in Java are the equivalent of functions in other languages. They must live inside a class.

1public class Calculator {
2    // Method with parameters and return type
3    public static int add(int a, int b) {
4        return a + b;
5    }
6 
7    // Method with no return value (void)
8    public static void greet(String name) {
9        System.out.println("Hello, " + name + "!");
10    }
11 
12    public static void main(String[] args) {
13        int result = add(5, 3);     // 8
14        greet("Alice");              // "Hello, Alice!"
15    }
16}

The method signature public static int add(int a, int b) tells you:

• public -- accessible from anywhere
• static -- belongs to the class, not an instance
• int -- returns an integer
• add -- the method name
• (int a, int b) -- takes two integer parameters

Classes and Objects (OOP Basics)

Java is an object-oriented language. Everything revolves around classes and objects.

A class is a blueprint. An object is an instance created from that blueprint.

1public class Dog {
2    // Fields (attributes)
3    String name;
4    String breed;
5    int age;
6 
7    // Constructor
8    public Dog(String name, String breed, int age) {
9        this.name = name;
10        this.breed = breed;
11        this.age = age;
12    }
13 
14    // Method
15    public String bark() {
16        return name + " says: Woof!";
17    }
18}

Using the class:

1Dog myDog = new Dog("Rex", "Labrador", 3);
2System.out.println(myDog.name);    // "Rex"
3System.out.println(myDog.bark());  // "Rex says: Woof!"

The Four Pillars of OOP

Java enforces object-oriented programming. The four pillars are:

1. Encapsulation -- hiding internal details behind methods

1public class BankAccount {
2    private double balance; // private -- cannot be accessed directly
3 
4    public double getBalance() {
5        return balance;
6    }
7 
8    public void deposit(double amount) {
9        if (amount > 0) {
10            balance += amount;
11        }
12    }
13}

1. Inheritance -- creating new classes based on existing ones

1public class Animal {
2    public void eat() {
3        System.out.println("Eating...");
4    }
5}
6 
7public class Cat extends Animal {
8    public void purr() {
9        System.out.println("Purring...");
10    }
11}
12 
13Cat cat = new Cat();
14cat.eat();  // inherited from Animal
15cat.purr(); // defined in Cat

1. Polymorphism -- treating objects of different classes through a common interface

1. Abstraction -- defining what something does without specifying how

Collections

Java's Collections framework provides powerful data structures.

ArrayList

1import java.util.ArrayList;
2 
3ArrayList<String> names = new ArrayList<>();
4names.add("Alice");
5names.add("Bob");
6names.add("Charlie");
7 
8System.out.println(names.get(0));  // "Alice"
9System.out.println(names.size());  // 3
10 
11names.remove("Bob");

HashMap

1import java.util.HashMap;
2 
3HashMap<String, Integer> scores = new HashMap<>();
4scores.put("Alice", 95);
5scores.put("Bob", 87);
6 
7System.out.println(scores.get("Alice")); // 95
8System.out.println(scores.containsKey("Charlie")); // false
9 
10for (String key : scores.keySet()) {
11    System.out.println(key + ": " + scores.get(key));
12}

Exception Handling

Java uses try-catch blocks to handle errors:

1try {
2    int result = 10 / 0;
3} catch (ArithmeticException e) {
4    System.out.println("Cannot divide by zero: " + e.getMessage());
5} finally {
6    System.out.println("This always runs");
7}

Common Beginner Mistakes

Mistake 1: Comparing Strings with ==

1String a = "hello";
2String b = new String("hello");
3 
4// Wrong -- compares references, not values
5if (a == b) { } // may be false!
6 
7// Correct -- compares content
8if (a.equals(b)) { } // true

Mistake 2: Forgetting Semicolons

Every statement in Java ends with a semicolon. Unlike Python, indentation is not significant -- semicolons and braces define code structure.

Mistake 3: Array Index Out of Bounds

1int[] nums = {1, 2, 3};
2System.out.println(nums[3]); // ArrayIndexOutOfBoundsException!
3// Valid indices are 0, 1, 2

Mistake 4: Not Understanding Static vs Instance

Static methods belong to the class. Instance methods belong to objects. You cannot call an instance method from a static context without creating an object first.

The Learning Path

Here is a practical order for learning Java:

Weeks 1-2: Variables, data types, strings, basic I/O, control flow (if/else, loops)

Weeks 3-4: Methods, arrays, and basic problem solving

Weeks 5-6: Classes, objects, constructors, encapsulation

Weeks 7-8: Inheritance, polymorphism, interfaces, ArrayList, HashMap

Month 3+: Exception handling, file I/O, generics, streams and lambdas, then Spring Boot for backend development

Start Learning Java Today

Java's verbosity can feel intimidating at first, but it enforces good habits -- explicit types, structured code, and proper error handling. These habits make you a better developer in any language.

Practice your Java syntax with our interactive Java exercises and keep our Java cheatsheet bookmarked for quick reference.

Related Reading

• Best Programming Language to Learn First in 2026 -- how Java compares to other first-language options
• Coding Interview Preparation Guide -- Java is widely accepted in coding interviews
• Understanding Functions in Programming -- Java methods follow the same fundamental principles as functions
• How to Practice Coding Effectively -- structured practice techniques for mastering Java syntax