Java Assignment

 1. Hello World:

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

2. Variables and Data Types:

java
public class DataTypesExample {
    public static void main(String[] args) {
        int age = 25;
        double height = 5.8;
        String name = "John Doe";

        System.out.println(name + " is " + age + " years old and is " + height + " feet tall.");
    }
}

3. Conditional Statements:

java
public class ConditionalExample {
    public static void main(String[] args) {
        int number = 10;

        if (number > 0) {
            System.out.println("The number is positive.");
        } else {
            System.out.println("The number is non-positive.");
        }
    }
}

4. Loops:

java
public class LoopExample {
    public static void main(String[] args) {
        for (int i = 1; i <= 5; i++) {
            System.out.println("Iteration " + i);
        }
    }
}

5. Arrays:

java
public class ArrayExample {
    public static void main(String[] args) {
        int[] numbers = {1, 2, 3, 4, 5};

        for (int num : numbers) {
            System.out.println(num);
        }
    }
}

6. Functions/Methods:

java
public class MethodExample {
    public static void main(String[] args) {
        int result = addNumbers(5, 7);
        System.out.println("Sum: " + result);
    }

    static int addNumbers(int a, int b) {
        return a + b;
    }
}

7. Object-Oriented Programming (OOP):

java
public class Car {
    String make;
    String model;

    public Car(String make, String model) {
        this.make = make;
        this.model = model;
    }

    public void displayInfo() {
        System.out.println("Car: " + make + " " + model);
    }

    public static void main(String[] args) {
        Car myCar = new Car("Toyota", "Camry");
        myCar.displayInfo();
    }
}

8. Exception Handling:

java
public class ExceptionExample {
    public static void main(String[] args) {
        try {
            int result = divide(10, 0);
            System.out.println("Result: " + result);
        } catch (ArithmeticException e) {
            System.out.println("Error: " + e.getMessage());
        }
    }

    static int divide(int a, int b) {
        return a / b;
    }
}

9. File I/O:

java
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class FileIOExample {
    public static void main(String[] args) {
        try {
            File file = new File("example.txt");
            FileWriter writer = new FileWriter(file);
            writer.write("Hello, File I/O!");
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

10. Android Basics (Button Click Event): (Assuming you have an Android project set up in Android Studio)

java
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import androidx.appcompat.app.AppCompatActivity; 
public class MainActivity extends AppCompatActivity { 
@Override
    protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button clickButton = findViewById(R.id.button);   clickButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // Handle button click event
                System.out.println("Button Clicked!");
            }
        });
    }
}

Remember to replace R.id.button with the actual ID of the button in your layout file (activity_main.xml).

1. We have the following code:

    public class Exercise {
    
    public static int additionFunction(){
        
        int x = 7;
        
        return x + y;
    }
}

--> Create a new variable called y and assign the value "3" to it

2. 

public class Exercise {

    public boolean playWithBooleans(){

        // Create your boolean variable "b1" here 

        return b1;

    }

}

Create a variable of type boolean and name it as "b1", assign true value to b1.

3. We have 2 booleans in this code:

  
public class Exercise {

  public boolean returnTrueExp(){
        
        boolean x = true;
        boolean y = true;

        // Add here the operator 
        return x     y;

    }
    
}

Your mission is to add a specific operator between x and y, so that this function will return true (according to the boolean expressions)

4. We need to concatenate 2 strings and return the result in our code:

   

public class Exercise {
    public String sayHello(){
        String str1 = "Hello ";
        String str2 = "My Friends";
        // Write your codes here 
        // use return statement to return the result
        return ;
    }
}

Join the two strings and return the result using the "return" statement.

5. Given the following code:

public class Exercise {
public boolean checkPositive(){
      int x = 99;
      
      // Write your conditional Statement Here
      
      // Use    return true; for returning if the condition is true;    
    }
}

Write a conditional statement, that checks if x is positive or not.

If x is positive, let the function returns true.

Else if x is negative, let the function returns false.

to return a true value, after your conditional statement just add:

return true;

6. Days of a Month

We need to create a conditional statement using a switch to check if "monthName" which is the variable that holds the month name , is a 31-days month or 30-days month.

Given this code:

 public class Exercise {
    public int daysOfMonth(){
    String monthName = "May";
    int number_Of_DaysInMonth = 0; 

    return number_Of_DaysInMonth;
    }
}

We need to return the number of days using an integer variable called: "number_Of_DaysInMonth"

it is initialised with zero value.

for example;

if January is 31 , then we assign number_Of_DaysInMonth = 31.

Note: Suppose that February is 28 days.

7. Making Use of Loops

We need to sum the numbers from  1 to 10 using the loops!

Given the following code:

public class Exercise {
    public int sumUpNumbers(){
        int sum = 0;
    
        // Write your loop here: Sum up numbers from 1 to 10
        return sum;   
    }
}

Write a loop that allows us to sum the numbers from 0 to 10 and stores the result in the "sum" variable.