Programming

Top 10 Java Programs Every School Student Should Know

Start your Java journey with these fun, practical programs designed specifically for school students—complete with easy-to-understand solutions!

Modern Age Coders Team
Modern Age Coders Team February 25, 2025
12 min read
School students learning Java programming with excitement

Table of Contents

Learning Java doesn't have to be scary or boring. If you're a school student just starting with programming, you're in the right place. This article covers 10 essential Java programs that will teach you the fundamentals while being fun and practical.

These aren't random exercises—they're carefully chosen programs that build on each other, teaching you important concepts like loops, conditions, arrays, and methods. By the end, you'll have a solid foundation in Java programming.

Each program includes complete working code, simple explanations, and practice challenges. Let's start coding!

ℹ️

Perfect for Beginners

These programs are designed for school students (Classes 8-12) who are new to Java. No prior programming experience needed—we'll explain everything step by step!

Why Learn These Programs?

Before we dive into the code, here's why these specific programs matter:

  • Build Strong Foundations: Each program teaches fundamental programming concepts
  • School Exam Preparation: These programs commonly appear in school exams and practicals
  • Logical Thinking: You'll develop problem-solving skills that help in all subjects
  • Confidence Building: Start simple and gradually tackle more challenging programs
  • Real-World Skills: Learn concepts used in actual software development

Ready? Let's write some code!

Let's start with the absolute basics—printing output to the screen. This is your first step into Java programming!

What You'll Learn

  • How to write a basic Java program
  • Using System.out.println() to display output
  • Understanding variables and data types
  • Basic program structure

Solution

public class PrintNameAge {
    public static void main(String[] args) {
        // Declare variables
        String name = "Rahul";
        int age = 15;
        
        // Print the information
        System.out.println("Hello! My name is " + name);
        System.out.println("I am " + age + " years old.");
        
        // You can also use printf for formatted output
        System.out.printf("In 5 years, I will be %d years old.%n", age + 5);
    }
}

Explanation

  • String name: Creates a variable to store text (your name)
  • int age: Creates a variable to store a whole number (your age)
  • System.out.println(): Prints text to the screen and moves to next line
  • + operator: Joins (concatenates) text and variables together
💡

Try This!

Change the name and age to your own. Add more lines to print your school name, favorite subject, or hobby!

Program #2: Simple Calculator (Add, Subtract, Multiply, Divide)

Let's build a calculator that can perform basic math operations. This teaches you about arithmetic operators and user input.

What You'll Learn

  • Arithmetic operators (+, -, *, /)
  • Taking input from users using Scanner
  • Performing calculations
  • Displaying results

Solution

import java.util.Scanner;

public class SimpleCalculator {
    public static void main(String[] args) {
        // Create Scanner object to read input
        Scanner scanner = new Scanner(System.in);
        
        // Get two numbers from user
        System.out.print("Enter first number: ");
        double num1 = scanner.nextDouble();
        
        System.out.print("Enter second number: ");
        double num2 = scanner.nextDouble();
        
        // Perform all operations
        double sum = num1 + num2;
        double difference = num1 - num2;
        double product = num1 * num2;
        double quotient = num1 / num2;
        
        // Display results
        System.out.println("\n--- Results ---");
        System.out.println(num1 + " + " + num2 + " = " + sum);
        System.out.println(num1 + " - " + num2 + " = " + difference);
        System.out.println(num1 + " * " + num2 + " = " + product);
        System.out.println(num1 + " / " + num2 + " = " + quotient);
        
        scanner.close();
    }
}

Explanation

  • Scanner: A tool to read input from the keyboard
  • nextDouble(): Reads a decimal number from user
  • double: Data type for numbers with decimals
  • Operators: + adds, - subtracts, * multiplies, / divides
💡

Challenge

Add a modulus operation (%) to find the remainder. Also, add error handling for division by zero!

Program #3: Check if a Number is Even or Odd

This program introduces you to conditional statements—making decisions in your code based on conditions.

What You'll Learn

  • If-else statements for decision making
  • Modulus operator (%) to find remainders
  • Boolean conditions (true/false)
  • Program flow control

Solution

import java.util.Scanner;

public class EvenOddChecker {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        
        // Check if number is even or odd
        if (number % 2 == 0) {
            System.out.println(number + " is an EVEN number.");
        } else {
            System.out.println(number + " is an ODD number.");
        }
        
        // Bonus: Check if positive, negative, or zero
        if (number > 0) {
            System.out.println("It is also a POSITIVE number.");
        } else if (number < 0) {
            System.out.println("It is also a NEGATIVE number.");
        } else {
            System.out.println("The number is ZERO.");
        }
        
        scanner.close();
    }
}

Explanation

  • % operator: Gives the remainder after division (5 % 2 = 1)
  • if-else: Executes different code based on conditions
  • == operator: Checks if two values are equal
  • Logic: If number divided by 2 has remainder 0, it's even

Program #4: Find the Largest of Three Numbers

Learn to compare multiple values and find the maximum—a common programming task.

What You'll Learn

  • Nested if-else statements
  • Comparison operators (>, <, >=, <=)
  • Logical operators (&&, ||)
  • Finding maximum values

Solution

import java.util.Scanner;

public class LargestNumber {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        // Get three numbers from user
        System.out.print("Enter first number: ");
        int num1 = scanner.nextInt();
        
        System.out.print("Enter second number: ");
        int num2 = scanner.nextInt();
        
        System.out.print("Enter third number: ");
        int num3 = scanner.nextInt();
        
        // Method 1: Using if-else
        int largest;
        if (num1 >= num2 && num1 >= num3) {
            largest = num1;
        } else if (num2 >= num1 && num2 >= num3) {
            largest = num2;
        } else {
            largest = num3;
        }
        
        System.out.println("\nThe largest number is: " + largest);
        
        // Method 2: Using Math.max()
        int max = Math.max(num1, Math.max(num2, num3));
        System.out.println("Using Math.max(): " + max);
        
        // Bonus: Find smallest too
        int smallest = Math.min(num1, Math.min(num2, num3));
        System.out.println("The smallest number is: " + smallest);
        
        scanner.close();
    }
}

Explanation

  • && operator: Means 'AND' - both conditions must be true
  • >= operator: Greater than or equal to
  • Math.max(): Built-in function to find maximum of two numbers
  • Nested Math.max(): Compare first two, then compare result with third
💡

Try This!

Modify the program to find the largest of 5 numbers. Can you do it without using Math.max()?

Program #5: Print Multiplication Table

Your first loop! Learn to repeat actions automatically—one of the most powerful concepts in programming.

What You'll Learn

  • For loops for repetition
  • Loop variables and counters
  • Formatted output
  • Automating repetitive tasks

Solution

import java.util.Scanner;

public class MultiplicationTable {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        
        System.out.println("\nMultiplication Table of " + number + ":");
        System.out.println("----------------------------");
        
        // Using for loop to print table
        for (int i = 1; i <= 10; i++) {
            int result = number * i;
            System.out.println(number + " x " + i + " = " + result);
        }
        
        // Bonus: Print table in reverse
        System.out.println("\nReverse Table:");
        for (int i = 10; i >= 1; i--) {
            System.out.println(number + " x " + i + " = " + (number * i));
        }
        
        scanner.close();
    }
}

Explanation

  • for loop: Repeats code a specific number of times
  • i = 1: Starting value (initialization)
  • i <= 10: Condition to continue (while this is true, loop continues)
  • i++: Increment (add 1 to i after each loop)
  • Loop body: Code inside { } runs each time
Learn Java Programming

Program #6: Check if a Number is Prime

Prime numbers are special—they're only divisible by 1 and themselves. This program teaches you to check mathematical properties.

What You'll Learn

  • While loops
  • Boolean variables (true/false)
  • Break statement to exit loops
  • Mathematical logic

Solution

import java.util.Scanner;

public class PrimeChecker {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        
        // Numbers less than 2 are not prime
        if (number < 2) {
            System.out.println(number + " is NOT a prime number.");
            return;
        }
        
        // Assume number is prime
        boolean isPrime = true;
        
        // Check if number is divisible by any number from 2 to number-1
        for (int i = 2; i <= number / 2; i++) {
            if (number % i == 0) {
                isPrime = false;
                break; // No need to check further
            }
        }
        
        // Display result
        if (isPrime) {
            System.out.println(number + " is a PRIME number!");
        } else {
            System.out.println(number + " is NOT a prime number.");
        }
        
        // Bonus: Print all prime numbers up to the entered number
        System.out.println("\nPrime numbers up to " + number + ":");
        for (int num = 2; num <= number; num++) {
            boolean prime = true;
            for (int i = 2; i <= num / 2; i++) {
                if (num % i == 0) {
                    prime = false;
                    break;
                }
            }
            if (prime) {
                System.out.print(num + " ");
            }
        }
        
        scanner.close();
    }
}

Explanation

  • boolean isPrime: Variable that stores true or false
  • break: Exits the loop immediately
  • Logic: If number is divisible by any number (remainder = 0), it's not prime
  • Optimization: Only check up to number/2 (no number larger than half can divide evenly)

Program #7: Reverse a Number

Learn to manipulate individual digits of a number—a fundamental skill for many programming problems.

What You'll Learn

  • While loops with conditions
  • Extracting digits using modulus
  • Building numbers digit by digit
  • Mathematical operations

Solution

import java.util.Scanner;

public class ReverseNumber {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        
        int original = number; // Save original number
        int reversed = 0;
        
        // Reverse the number
        while (number != 0) {
            int digit = number % 10;      // Get last digit
            reversed = reversed * 10 + digit;  // Add digit to reversed number
            number = number / 10;         // Remove last digit
        }
        
        System.out.println("Original number: " + original);
        System.out.println("Reversed number: " + reversed);
        
        // Bonus: Check if number is palindrome
        if (original == reversed) {
            System.out.println(original + " is a PALINDROME!");
        } else {
            System.out.println(original + " is NOT a palindrome.");
        }
        
        scanner.close();
    }
}

Explanation

  • number % 10: Gets the last digit (1234 % 10 = 4)
  • number / 10: Removes the last digit (1234 / 10 = 123)
  • reversed * 10 + digit: Builds reversed number (0 → 4 → 43 → 432 → 4321)
  • Palindrome: Number that reads same forwards and backwards (121, 1331)
💡

Challenge

Try reversing a string instead of a number. Hint: Use a for loop to go through the string backwards!

Program #8: Find Factorial of a Number

Factorial is a mathematical operation where you multiply a number by all positive integers less than it. Great for learning recursion!

What You'll Learn

  • Recursion (function calling itself)
  • Iterative vs recursive approaches
  • Base cases in recursion
  • Mathematical calculations

Solution

import java.util.Scanner;

public class Factorial {
    
    // Method 1: Using loop (Iterative)
    public static long factorialIterative(int n) {
        long result = 1;
        for (int i = 1; i <= n; i++) {
            result *= i;  // Same as: result = result * i
        }
        return result;
    }
    
    // Method 2: Using recursion
    public static long factorialRecursive(int n) {
        // Base case: factorial of 0 or 1 is 1
        if (n == 0 || n == 1) {
            return 1;
        }
        // Recursive case: n! = n × (n-1)!
        return n * factorialRecursive(n - 1);
    }
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        
        if (number < 0) {
            System.out.println("Factorial is not defined for negative numbers.");
        } else {
            long resultIterative = factorialIterative(number);
            System.out.println("Factorial (Iterative): " + number + "! = " + resultIterative);
            
            long resultRecursive = factorialRecursive(number);
            System.out.println("Factorial (Recursive): " + number + "! = " + resultRecursive);
            
            // Show the calculation
            System.out.print("\nCalculation: " + number + "! = ");
            for (int i = number; i >= 1; i--) {
                System.out.print(i);
                if (i > 1) System.out.print(" × ");
            }
            System.out.println(" = " + resultIterative);
        }
        
        scanner.close();
    }
}

Explanation

  • Factorial: 5! = 5 × 4 × 3 × 2 × 1 = 120
  • Iterative: Uses a loop to multiply numbers
  • Recursive: Function calls itself with smaller values
  • Base case: Stopping condition for recursion (0! = 1, 1! = 1)
  • long: Used instead of int because factorials get very large

Pattern printing is fun and teaches you nested loops—loops inside loops!

What You'll Learn

  • Nested loops (loop inside another loop)
  • Understanding rows and columns
  • Pattern logic and visualization
  • Creative programming

Solution

import java.util.Scanner;

public class PatternPrinting {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter number of rows: ");
        int rows = scanner.nextInt();
        
        // Pattern 1: Right-angled triangle
        System.out.println("\nPattern 1: Right Triangle");
        for (int i = 1; i <= rows; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        
        // Pattern 2: Inverted triangle
        System.out.println("\nPattern 2: Inverted Triangle");
        for (int i = rows; i >= 1; i--) {
            for (int j = 1; j <= i; j++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        
        // Pattern 3: Pyramid
        System.out.println("\nPattern 3: Pyramid");
        for (int i = 1; i <= rows; i++) {
            // Print spaces
            for (int j = 1; j <= rows - i; j++) {
                System.out.print("  ");
            }
            // Print stars
            for (int j = 1; j <= 2 * i - 1; j++) {
                System.out.print("* ");
            }
            System.out.println();
        }
        
        // Pattern 4: Number triangle
        System.out.println("\nPattern 4: Number Triangle");
        for (int i = 1; i <= rows; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print(j + " ");
            }
            System.out.println();
        }
        
        // Pattern 5: Floyd's Triangle
        System.out.println("\nPattern 5: Floyd's Triangle");
        int number = 1;
        for (int i = 1; i <= rows; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print(number + " ");
                number++;
            }
            System.out.println();
        }
        
        scanner.close();
    }
}

Explanation

  • Outer loop: Controls rows (how many lines)
  • Inner loop: Controls columns (what to print in each line)
  • Nested loops: Inner loop runs completely for each iteration of outer loop
  • Spaces: Used to create alignment in pyramid patterns
  • Floyd's Triangle: Continuous numbers arranged in triangular form
Examples of different star and number patterns
Pattern printing helps visualize nested loops
💡

Challenge

Try creating a diamond pattern or a hollow square! These require combining multiple pattern techniques.

Program #10: Simple Array Operations

Arrays let you store multiple values in one variable. This is your introduction to data structures!

What You'll Learn

  • Creating and initializing arrays
  • Accessing array elements
  • Looping through arrays
  • Common array operations (sum, average, max, min)

Solution

import java.util.Scanner;

public class ArrayOperations {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("How many numbers do you want to enter? ");
        int size = scanner.nextInt();
        
        // Create array
        int[] numbers = new int[size];
        
        // Input array elements
        System.out.println("Enter " + size + " numbers:");
        for (int i = 0; i < size; i++) {
            System.out.print("Number " + (i + 1) + ": ");
            numbers[i] = scanner.nextInt();
        }
        
        // Display array
        System.out.print("\nYour numbers: ");
        for (int num : numbers) {
            System.out.print(num + " ");
        }
        System.out.println();
        
        // Calculate sum
        int sum = 0;
        for (int num : numbers) {
            sum += num;
        }
        System.out.println("\nSum: " + sum);
        
        // Calculate average
        double average = (double) sum / size;
        System.out.println("Average: " + average);
        
        // Find maximum
        int max = numbers[0];
        for (int num : numbers) {
            if (num > max) {
                max = num;
            }
        }
        System.out.println("Maximum: " + max);
        
        // Find minimum
        int min = numbers[0];
        for (int num : numbers) {
            if (num < min) {
                min = num;
            }
        }
        System.out.println("Minimum: " + min);
        
        // Search for a number
        System.out.print("\nEnter a number to search: ");
        int search = scanner.nextInt();
        boolean found = false;
        int position = -1;
        
        for (int i = 0; i < numbers.length; i++) {
            if (numbers[i] == search) {
                found = true;
                position = i;
                break;
            }
        }
        
        if (found) {
            System.out.println(search + " found at position " + (position + 1));
        } else {
            System.out.println(search + " not found in the array.");
        }
        
        scanner.close();
    }
}

Explanation

  • int[] numbers: Declares an array of integers
  • new int[size]: Creates array with specified size
  • numbers[i]: Accesses element at index i (arrays start at 0)
  • Enhanced for loop: for (int num : numbers) - easier way to loop through arrays
  • numbers.length: Property that gives the size of array
✅

Congratulations!

You've completed all 10 programs! You now know variables, loops, conditions, methods, recursion, and arrays—the building blocks of Java programming!

Continue Learning Java

Practice Tips for School Students

Now that you've seen all 10 programs, here's how to practice effectively:

1. Type, Don't Copy-Paste

Always type the code yourself. Your fingers need to learn the syntax, and typing helps you remember better than copying.

2. Experiment and Break Things

Change values, modify conditions, add new features. See what happens when you break the code—that's how you learn!

3. Explain to Someone Else

Try teaching these programs to a friend or family member. If you can explain it, you truly understand it.

4. Practice Daily

Even 20-30 minutes daily is better than 3 hours once a week. Consistency builds skills faster.

5. Create Your Own Variations

  • Modify the calculator to include more operations
  • Create different pattern designs
  • Build a simple grade calculator using arrays
  • Make a number guessing game
  • Create a simple quiz program
💡

Study Schedule

Week 1: Programs 1-3 | Week 2: Programs 4-6 | Week 3: Programs 7-8 | Week 4: Programs 9-10 | Week 5: Create your own programs!

Common Mistakes to Avoid

  • Forgetting semicolons (;): Every statement in Java needs to end with a semicolon
  • Case sensitivity: 'Number' and 'number' are different in Java
  • Array index errors: Remember arrays start at 0, not 1
  • Not closing Scanner: Always use scanner.close() at the end
  • Integer division: 5/2 gives 2, not 2.5 (use double for decimals)
  • Infinite loops: Make sure your loop condition eventually becomes false

Quick Reference: Java Basics

Here's a handy reference for the concepts you've learned:

Data Types

  • int: Whole numbers (5, -10, 1000)
  • double: Decimal numbers (3.14, -0.5, 99.99)
  • String: Text ("Hello", "Java")
  • boolean: True or false
  • char: Single character ('A', '5', '
Modern Age Coders Team

About Modern Age Coders Team

Expert educators passionate about making coding accessible and fun for learners of all ages.

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)

Operators

Control Structures

// If-else
if (condition) {
    // code
} else {
    // code
}

// For loop
for (int i = 0; i < 10; i++) {
    // code
}

// While loop
while (condition) {
    // code
}

// Enhanced for loop (for arrays)
for (int num : array) {
    // code
}

Next Steps: Where to Go From Here

You've mastered the basics! Here's what to learn next:

  1. Object-Oriented Programming: Learn about classes, objects, inheritance
  2. More Data Structures: ArrayList, HashMap, LinkedList
  3. String Manipulation: Working with text in detail
  4. File Handling: Reading from and writing to files
  5. Exception Handling: Dealing with errors gracefully
  6. GUI Programming: Creating windows and buttons (Swing/JavaFX)

Check out our complete Java courses for teens to continue your learning journey with structured lessons and projects.

Fun Project Ideas

Ready to build something cool? Try these projects using what you've learned:

✅

Challenge Yourself

Pick one project idea and build it this week! Combine multiple concepts you've learned. Don't worry about making it perfect—just start building!

Join Our Coding Community

Frequently Asked Questions

No! Focus on understanding the logic and concepts. Once you understand how they work, you can recreate them anytime. Practice regularly instead of memorizing.

Start with Program #1 and work your way through in order. Each program builds on concepts from previous ones, so the sequence matters for beginners.

If you practice 30-60 minutes daily, you can understand all 10 programs in 2-3 weeks. Take your time—understanding is more important than speed.

Errors are normal! Read the error message carefully—it tells you what's wrong and which line. Common issues: missing semicolons, typos, wrong brackets. Debug step by step.

Yes! These are standard programs that appear in school exams. Practice writing them from memory without looking at solutions. Understand the logic, not just the code.

You need JDK (Java Development Kit) installed on your computer. You can use any text editor, but IDEs like Eclipse, IntelliJ IDEA, or NetBeans make coding easier.

These 10 programs cover the core concepts for school-level Java. Your school might teach additional topics like classes and objects, which you should learn from your textbook or teacher.

Modify these programs, create variations, solve problems on websites like HackerRank or Codingame (beginner sections), and most importantly—build your own small projects!

Conclusion

Congratulations! You've just learned 10 essential Java programs that form the foundation of programming. From printing your name to working with arrays, you've covered variables, loops, conditions, methods, recursion, and data structures.

These aren't just school exercises—they're building blocks for real programming. Every professional developer uses these concepts daily. The calculator you built? That's how real calculators work. The array operations? That's how apps manage data. The patterns? That's how graphics are created.

The difference between students who succeed in programming and those who struggle isn't talent—it's practice. The students who succeed are the ones who:

You now have everything you need to start. Pick Program #1, open your IDE, and start typing. Make mistakes. Get errors. Fix them. That's how you learn.

Remember: every expert programmer was once a beginner who didn't give up. Every complex app started with simple programs like these. Your coding journey starts here, with these 10 programs.

Need more help? Want structured lessons with projects and mentorship? Check out our Java courses for school students. Or reach out to us with questions—we're here to help you succeed!

✅

You're Ready!

You have the knowledge. You have the code. Now all you need is to start practicing. Open your IDE, pick a program, and start coding. Your programming journey begins today!

Start Learning Java Today
Modern Age Coders Team

About Modern Age Coders Team

Expert educators passionate about making coding accessible and fun for learners of all ages.

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