Java Programming for Beginners Tools, Skills and Resources

public class HelloJava {
    public static void main(String[] args) {
        String name = "Uncodemy learner";
        int year = 2026;
        System.out.println("Hello, " + name + "!");
        System.out.println("Starting Java in " + year);
    }
}

# Check the installation
java -version
javac -version

# Compile and run (file name must match the class name)
javac HelloJava.java
java HelloJava

# Java 11+ can also run a single file directly
java HelloJava.java

import java.util.Scanner;

public class GradeBook {
    static double average(int[] marks) {
        int total = 0;
        for (int m : marks) total += m;
        return (double) total / marks.length;
    }

    static String grade(double avg) {
        if (avg >= 85) return "A";
        else if (avg >= 70) return "B";
        else if (avg >= 50) return "C";
        return "Needs improvement";
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[] marks = new int[3];
        for (int i = 0; i < marks.length; i++) {
            System.out.print("Enter mark " + (i + 1) + ": ");
            marks[i] = sc.nextInt();
        }
        double avg = average(marks);
        System.out.printf("Average %.1f, grade %s%n", avg, grade(avg));
    }
}

import java.util.ArrayList;
import java.util.List;

class Student {
    private final String name;
    private final List<Integer> marks = new ArrayList<>();

    Student(String name) { this.name = name; }

    void addMark(int mark) { marks.add(mark); }

    double average() {
        return marks.stream().mapToInt(Integer::intValue).average().orElse(0);
    }

    String getName() { return name; }
}

public class School {
    public static void main(String[] args) {
        Student s = new Student("Priya");
        s.addMark(78);
        s.addMark(91);
        System.out.println(s.getName() + ": " + s.average());
    }
}

How to use resources each day (about 90 minutes)

20 min  Read one topic from the official tutorial or book
40 min  Write 2-3 small programs using that topic
15 min  Look up any class you used in the API docs
15 min  One practice exercise on a coding site

Weekend: build or extend a small project

Starter bookmark list (keep it short):

1. dev.java/learn                 - official learning path
2. docs.oracle.com/en/java/javase - API documentation
3. One coding practice site
4. One beginner book
5. Your own GitHub repo of exercises

Rule: add a new resource only when one of these
no longer helps you.

Week 1  Setup, variables, types, input/output
Week 2  Conditions and loops (20 small programs)
Week 3  Arrays and methods
Week 4  Classes and objects
Week 5  Inheritance, interfaces, polymorphism
Week 6  Collections: ArrayList, HashMap, HashSet
Week 7  Exceptions and file handling
Week 8  Mini project: contact book or library system

Date: ________
Topic: ________________
Programs written today:
1.
2.
3.
Error I met and how I fixed it:
______________________
One thing I can now explain:
______________________
Pushed to GitHub?  Yes / No

Beginner Java project ideas

1. Number guessing game (Random, loops)
2. Student grade manager (classes, ArrayList)
3. Bank account simulator (encapsulation)
4. Contact book saved to file (I/O, exceptions)
5. Library system (collections, OOP design)

For each project: README, sample run output,
and one feature you added on your own.