16 files changed, 486 insertions, 25 deletions

diff --git a/java/alist.txt b/java/alist.txt
index 2dcc72d..d549684 100644
--- a/java/alist.txt
+++ b/java/alist.txt
@@ -4,11 +4,11 @@ StringOperations #
 MatrixOperations #
 AddTwoNumbers #
 CylinderCalculations #
-ComplexCalculations
-FindNumberInArray 
-StaticExecution
-SingletonExample 
-StudentsArray
-BankAccountExample
-ShapeAreaCalculations
+ComplexCalculations #
+FindNumberInArray #
+StaticExecution #
+SingletonExample #
+StudentsArray #
+BankAccountExample #
+ShapeAreaCalculations #
 AbstractShapeCalculations
diff --git a/java/code/ShapeAreaCalculations.java b/java/code/ShapeAreaCalculations.java
index 0d00bff..ca20d39 100644
--- a/java/code/ShapeAreaCalculations.java
+++ b/java/code/ShapeAreaCalculations.java
@@ -1,4 +1,5 @@
 import java.util.Scanner;
+import java.util.InputMismatchException;
 
 class Shape {
     // Calculates the area of a triangle.
@@ -20,11 +21,11 @@ class Shape {
     }
 }
 
-class AreaCalc {
+class ShapeAreaCalculations {
     public static void main(String args[]) {
-        var sc = new Scanner(System.in);
+	try (var sc = new Scanner(System.in)) {
         System.out.println("Choose the shape: ");
-        System.out.println("1. Triangle\n2. Rectangle\n3. Square\n4.Circle");
+        System.out.println("1. Triangle\n2. Rectangle\n3. Square\n4. Circle");
         System.out.print("Enter your choice: ");
         var choice = sc.nextInt();
         switch (choice) {
@@ -55,5 +56,8 @@ class AreaCalc {
                 System.out.println("Invalid choice");
                 break;
         }
+	} catch (InputMismatchException e) {
+            System.err.println("Invalid number given as input");
+        }
     }
 }
diff --git a/java/output/BankAccountExample.typ b/java/output/BankAccountExample.typ
new file mode 100644
index 0000000..779f5ff
--- /dev/null
+++ b/java/output/BankAccountExample.typ
@@ -0,0 +1,124 @@
+#import "/template.typ": highlight-output
+#highlight-output[```
+$ java BankAccountExample
+Menu-driven program for operating bank accounts:
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 1
+Enter details of bank account:
+  Name: Lee Heoksoo
+  Address: Sindang-dong, Seoul
+  Account No.: 120045387091
+  Balance: 71623500
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 2
+Enter account number: 120045387091
+Customer details: 
+  Name: Lee Heoksoo
+  Address: Sindang-dong, Seoul
+  Account Number: 120045387091
+  Balance: 71623500.00
+
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 1
+Enter details of bank account:
+  Name: Axel Schauer
+  Address: Eidelstedt, Hamburg
+  Account No.: 582978
+  Balance: 36400
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 4
+Enter account number: 42000
+Could not find a bank account with the given account number.
+Try again.
+
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 4
+Enter account number: 4200
+Could not find a bank account with the given account number.
+Try again.
+
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 3
+Enter account number: 12000
+Could not find a bank account with the given account number.
+Try again.
+
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 5
+Enter account number: 582978
+Are you sure about closing your account (y/n): y
+Account closing successful.
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 2
+Enter account number: 582978
+Could not find a bank account with the given account number.
+Try again.
+
+Menu:
+ 1. Create bank account
+ 2. Display bank account details
+ 3. Deposit money
+ 4. Withdraw money
+ 5. Close bank account
+ 6. Exit
+
+Enter your choice: 6
+Bye.
+```]
+
diff --git a/java/output/ComplexCalculations.typ b/java/output/ComplexCalculations.typ
new file mode 100644
index 0000000..1b10fe7
--- /dev/null
+++ b/java/output/ComplexCalculations.typ
@@ -0,0 +1,20 @@
+#import "/template.typ": highlight-output
+#highlight-output[```
+$ java ComplexCalculations
+First complex number:-
+  Enter real part: 2
+  Enter imaginary part: -3
+Second complex number:-
+  Enter real part: 5
+  Enter imaginary part: 2
+(2.0 - 3.0i) + (5.0 + 2.0i) = 7.0 - 1.0i
+$ java ComplexCalculations
+First complex number:-
+  Enter real part: 1.5
+  Enter imaginary part: -6.5
+Second complex number:-
+  Enter real part: 4.23
+  Enter imaginary part: 3.7
+(1.5 - 6.5i) + (4.23 + 3.7i) = 5.73 - 2.8i
+```]
+
diff --git a/java/output/FindNumberInArray.typ b/java/output/FindNumberInArray.typ
new file mode 100644
index 0000000..9b71bb4
--- /dev/null
+++ b/java/output/FindNumberInArray.typ
@@ -0,0 +1,15 @@
+#import "/template.typ": highlight-output
+#highlight-output[```
+$ java FindNumberInArray
+Enter length: 5
+Enter array elements: 4 7 3 2 9
+Given: An array of numbers with 5 elements: 4.0 7.0 3.0 2.0 9.0
+Enter element to find in array: 7
+The number 7.0 was found in the array at position 2.
+$ java FindNumberInArray
+Enter length: 4
+Enter array elements: 5 9 0 3
+Given: An array of numbers with 4 elements: 5.0 9.0 0.0 3.0
+Enter element to find in array: 4
+Could not find the number 4.0 in the array.
+```]
diff --git a/java/output/ShapeAreaCalculations.typ b/java/output/ShapeAreaCalculations.typ
new file mode 100644
index 0000000..05f14e6
--- /dev/null
+++ b/java/output/ShapeAreaCalculations.typ
@@ -0,0 +1,40 @@
+#import "/template.typ": highlight-output
+#highlight-output[```
+$ java ShapeAreaCalculations
+Choose the shape: 
+1. Triangle
+2. Rectangle
+3. Square
+4. Circle
+Enter your choice: 1
+Enter sides: 6 8 10
+Area of a triangle: 24.0
+$ java ShapeAreaCalculations
+Choose the shape: 
+1. Triangle
+2. Rectangle
+3. Square
+4. Circle
+Enter your choice: 2
+Enter length and width: 23 14
+Area of a rectangle: 322
+$ java ShapeAreaCalculations
+Choose the shape: 
+1. Triangle
+2. Rectangle
+3. Square
+4. Circle
+Enter your choice: 3
+Enter side length: 7
+Area of a square: 49
+$ java ShapeAreaCalculations
+Choose the shape: 
+1. Triangle
+2. Rectangle
+3. Square
+4. Circle
+Enter your choice: 4
+Enter radius: 5
+Area of a square: 78.53981633974483
+```]
+
diff --git a/java/output/StudentsArray.typ b/java/output/StudentsArray.typ
new file mode 100644
index 0000000..358a15b
--- /dev/null
+++ b/java/output/StudentsArray.typ
@@ -0,0 +1,55 @@
+#import "/template.typ": highlight-output
+#highlight-output[```
+$ java StudentsArray
+Enter the number of students: 
+2
+Enter the details of the students:
+For student 1: Enter the details of the student:
+Enter Roll no.: 1
+Enter name: Lee Haseol
+Enter stream: Science
+For subject 1: Enter details of subject:
+Enter title: Physics
+Enter theory marks: 94
+For subject 2: Enter details of subject:
+Enter title: Chemistry
+Enter theory marks: 96
+For subject 3: Enter details of subject:
+Enter title: Mathematics
+Enter theory marks: 98
+For student 2: Enter the details of the student:
+Enter Roll no.: 43
+Enter name: Lin Feng
+Enter stream: Arts
+For subject 1: Enter details of subject:
+Enter title: History
+Enter theory marks: 47
+For subject 2: Enter details of subject:
+Enter title: Caligraphy
+Enter theory marks: 56
+For subject 3: Enter details of subject:
+Enter title: Philosophy
+Enter theory marks: 72
+Displaying the details of the students:
+
+For student 1: 
+Student details:
+  Roll No.: 1
+  Name: Lee Haseol
+  Stream: Science
+  Marks obtained in Physics: 94
+  Marks obtained in Chemistry: 96
+  Marks obtained in Mathematics: 98
+  Average percentage: 96.00%
+
+For student 2: 
+Student details:
+  Roll No.: 43
+  Name: Lin Feng
+  Stream: Arts
+  Marks obtained in History: 47
+  Marks obtained in Caligraphy: 56
+  Marks obtained in Philosophy: 72
+  Average percentage: 58.33%
+```]
+
diff --git a/java/state.sql b/java/state.sql
index 24bc8fe..d0c22bd 100644
--- a/java/state.sql
+++ b/java/state.sql
@@ -11,13 +11,13 @@ INSERT INTO `assignments` VALUES
     ('MatrixOperations', 1, 1, 1, 1),
     ('AddTwoNumbers', 1, 1, 1, 1),
     ('CylinderCalculations', 1, 1, 1, 1),
-    ('ComplexCalculations', 1, 0, 1, 1),
-    ('FindNumberInArray', 1, 0, 0, 1),
+    ('ComplexCalculations', 1, 1, 1, 1),
+    ('FindNumberInArray', 1, 1, 1, 1),
     ('StaticExecution', 1, 1, 1, 1),
-    ('SingletonExample', 1, 1, 0, 1),
-    ('StudentsArray', 1, 0, 0, 1),
-    ('BankAccountExample', 1, 0, 0, 1),
-    ('ShapeAreaCalculations', 1, 0, 0, 0),
+    ('SingletonExample', 1, 1, 1, 1),
+    ('StudentsArray', 1, 1, 1, 1),
+    ('BankAccountExample', 1, 1, 1, 1),
+    ('ShapeAreaCalculations', 1, 1, 1, 0),
     ('AbstractShapeCalculations', 1, 0, 0, 0),
     ('ParentWithTwoChildren', 1, 1, 1, 0),
     ('CuboidCalculations', 1, 1, 0, 0),
diff --git a/java/text/BankAccountExample.typ b/java/text/BankAccountExample.typ
new file mode 100644
index 0000000..2cb1cc8
--- /dev/null
+++ b/java/text/BankAccountExample.typ
@@ -0,0 +1,57 @@
+#import "/template.typ": *
+#show: A => apply(A)
+#set raw(lang: "java-new")
+#set par(leading: 0.5em)
+
+#assignment(12, block: true)[
+  Write a program wherein design a class to represent a bank account. Include the following:
+  #pad(left: 1em)[
+  / Fields :
+    - Name of the depositor
+    - Address of the depositor
+    - Account number
+    - Balance amount in the account
+  / Methods :
+    - To assign initial values
+    - To deposit an amount
+    - To withdraw an amount after checking balance
+    - To display the name, address and balance of a customer.
+  ]
+  From `main()` create object and call these methods.
+]
+
+#scos("BankAccountExample")
+
+=== Discussion
+
+#skind[Classes, interfaces and methods used from Java standard library]
+
+- `java.util.ArrayList<E>` class provides a dynamic array implementation, allowing for the flexible storage and manipulation of elements in a resizable list.
+  - `boolean add(E)`: Adds the specified element to the end of the list.
+  - `E remove(int)`: Removes the element at the specified position in the list.
+  - `int size()`: Returns the number of elements in the list.
+- `java.util.Scanner` class:
+  - `String nextLine()`: Scan a line of text from the input stream.
+  - `long nextLong()`: Scan a `long` value from the input stream.
+  - `double nextDouble()`: Scan a `double` value from the input stream.
+
+#skind[Classes and methods implemented in the program]
+
+- The `BankAccount` class represents a bank account with details like name, address, account number, and balance.
+  - Constructor `BankAccount(String, String, long, double)`: Create a bank account with the given details.
+  - `static BankAccount takeInput(Scanner)`: Takes input for a bank account from the user.
+  - `long getAccountNo()`: Returns the account number of the bank account.
+  - `double getBalance()`: Returns the balance of the bank account.
+  - `boolean equals(Object)`: Compares bank accounts based on account number.
+  - `void deposit(double)`: Deposits money into the account.
+  - `static String formatBalance(double)`: Formats a balance value for display.
+  - `void withdraw(double) throws Exception`: Withdraws money from the account, handling exceptions.
+  - `void display()`: Displays the details of the bank account.
+  - `static BankAccount lookup(ArrayList<BankAccount>, long)`: Looks up a bank account in the list based on account number.
+
+- The `BankAccountExample` class contains the main program for interacting with bank accounts through a menu:
+  - `static void menu()`: Displays a menu of operations.
+  - `static BankAccount findAccount(Scanner, ArrayList<BankAccount>)`: Finds a bank account based on user input.
+  - `public static void main(String[])`: Implements a menu-driven program for managing bank accounts, allowing creation, display, deposit, withdrawal, and closure of accounts.
+  
+#signature()
diff --git a/java/text/ComplexCalculations.typ b/java/text/ComplexCalculations.typ
index b8df211..ffa9304 100644
--- a/java/text/ComplexCalculations.typ
+++ b/java/text/ComplexCalculations.typ
@@ -1,9 +1,9 @@
 #import "/template.typ": *
 #show: A => apply(A)
 #set raw(lang: "java-new")
-#set par(leading: 0.5em)
+#set par(leading: 0.65em)
 
-#assignment(6)[
+#assignment(7)[
   Write a program to add two complex numbers using concept of methods returning objects and methods taking objects as parameters.
 ]
 
@@ -23,9 +23,10 @@
 - The `Complex` class objects represents a a complex number.
   - Constructor `Complex(double, double)`: Create a complex number object from the provided real and imaginary parts.
   - `public String toString()` method returns the string representation of the complex number.
-- The `ComplexOperations` class 
-- The `CylinderCalculationsCLI` orchestrates a main program with:
-  - `public static void main(String[])`: Creates a cylinder object with its radius and height given as command-line arguments.
-- The `CylinderCalculationsScan` orchestrates a main program with:
-  - `public static void main(String[])`: Creates a cylinder object with its radius and height taken from user using `java.util.Scanner`.
+- The `ComplexOperations` class contains operations that can be performed on `Complex` objects.
+  - `static Complex add(Complex a, Complex b) `: Returns the sum of two complex numbers provided.
+- The `ComplexCalculations` orchestrates a main program with:
+  - `static Complex takeComplexInput()`: Returns the complex number provided by the user.
+  - `public static void main(String[])`: Performs addition of two complex numbers.
+
 #signature()
diff --git a/java/text/FindNumberInArray.typ b/java/text/FindNumberInArray.typ
new file mode 100644
index 0000000..9c6a4bd
--- /dev/null
+++ b/java/text/FindNumberInArray.typ
@@ -0,0 +1,36 @@
+#import "/template.typ": *
+#show: A => apply(A)
+#set raw(lang: "java-new")
+#set par(leading: 0.7em)
+
+#assignment(8, pad: true)[
+  Write a program to find a number from an array of number objects.
+]
+
+#scos("FindNumberInArray")
+
+#v(1em)
+
+=== Discussion
+
+#skind[Classes, interfaces and methods used from Java standard library]
+
+- `java.util.Scanner` class:
+  - `int nextInt()`: Scan an `int` value from the input stream.
+  - `double nextDouble()`: Scan a `double` value from the input stream.
+- `java.util.InputMismatchException` is thrown by the methods of `Scanner` class when encountering invalid input.
+
+#skind[Classes and methods implemented in the program]
+
+- The `Number` class objects represent a `double` value and provide methods for equality comparison.
+  - Constructor `Number(double)`: Create a number object for the provided value.
+  - `double valueOf()`: Returns the underlying number.
+  - `boolean equals(Object)`: Compares the equality of the number with another object.
+- The `NumberArray` class manages an array of `Number` objects.
+  - Constructor `NumberArray(double[])`: Create a `NumberArray` object from an array of `double` values.
+  - `int find(Number)`: Find the position of a given `Number` in the array, or return -1 if not found.
+  - `void display()`: Display the elements of the array.
+- The `FindNumberInArray` class contains the main program for finding a number in an array:
+  - `public static void main(String[])`: Takes user input for the length and elements of an array, creates a `NumberArray`, and finds a specified number in the array.
+  
+#signature()
diff --git a/java/text/ShapeAreaCalculations.typ b/java/text/ShapeAreaCalculations.typ
new file mode 100644
index 0000000..f34c1a0
--- /dev/null
+++ b/java/text/ShapeAreaCalculations.typ
@@ -0,0 +1,27 @@
+#import "/template.typ": *
+#show: A => apply(A)
+#set raw(lang: "java-new")
+#set par(leading: 0.6em)
+
+#assignment(13)[
+  Write a program to create a class `Shape` with 4 methods to calculate the areas of triangle, rectangle, square, and circle using method overloading.
+]
+
+#scos("ShapeAreaCalculations")
+
+=== Discussion
+
+#skind[Classes and methods implemented in the program]
+
+- The `Shape` class provides static methods for calculating the area of different geometric shapes:
+  - `static double area(double a, double b, double c)`: Calculates the area of a triangle using its side lengths.
+  - `static int area(int length, int width)`: Calculates the area of a rectangle using its length and width.
+  - `static int area(int sideLength)`: Calculates the area of a square using its side length.
+  - `static double area(double radius)`: Calculates the area of a circle using its radius.
+
+- The `ShapeAreaCalculations` class contains the main program for calculating the area of geometric shapes based on user input through a menu-driven interface:
+  - `static void menu()`: Displays a menu of shape choices.
+  - `public static void main(String[])`: Implements a menu-driven program for calculating the area of different shapes (_i.e._ triangle, rectangle, square, or circle) based on user input.
+
+  
+#signature()
diff --git a/java/text/SingletonExample.typ b/java/text/SingletonExample.typ
new file mode 100644
index 0000000..84a5cff
--- /dev/null
+++ b/java/text/SingletonExample.typ
@@ -0,0 +1,24 @@
+#import "/template.typ": *
+#show: A => apply(A)
+#set raw(lang: "java-new")
+#set par(leading: 0.4em)
+
+#assignment(10, reduce-gap: true, pad: true)[
+  Write a program to implement a singleton class.
+]
+#v(-1em)
+#scos("SingletonExample")
+
+=== Discussion
+
+#skind[Classes and methods implemented in the program]
+
+- The `Singleton` class implements the Singleton design pattern to ensure a single instance of the class is created.
+  - `private static Singleton instance`: Private static variable to hold the single instance of the class.
+  - `private Singleton()`: Private constructor to prevent external instantiation and prints a message when the instance is created.
+  - `public static Singleton getInstance()`: Public method to retrieve the singleton instance. If the instance does not exist, it creates one and prints a message.
+  
+- The `SingletonExample` class contains the main program to demonstrate the Singleton pattern:
+  - `public static void main(String[])`: Creates two instances of `Singleton` using the `getInstance()` method and checks if they refer to the same instance.
+    - If `s1` and `s2` reference the same object, it prints "The singleton instances are identical."  
+#signature()
diff --git a/java/text/StaticExecution.typ b/java/text/StaticExecution.typ
index 00b4ed0..d89c8f0 100644
--- a/java/text/StaticExecution.typ
+++ b/java/text/StaticExecution.typ
@@ -3,10 +3,10 @@
 #set raw(lang: "java-new")
 #set par(leading: 0.75em)
 
-#assignment(10)[
+#assignment(9)[
   Write a program to show that `static` blocks get executed before any object creation and implement the use of static variable to count the number of objects.
 ]
-
+#v(-1em)
 #scos("StaticExecution")
 
 === Discussion
diff --git a/java/text/StudentsArray.typ b/java/text/StudentsArray.typ
new file mode 100644
index 0000000..18921ef
--- /dev/null
+++ b/java/text/StudentsArray.typ
@@ -0,0 +1,38 @@
+#import "/template.typ": *
+#show: A => apply(A)
+#set raw(lang: "java-new")
+#set par(leading: 0.6em)
+
+#assignment(11, block: true)[
+  Write a program to make a student class with attributes for _roll number_, _name_ and _stream_. Assume that a student studies 3 subjects having full marks of 100 each. Each subject has a _title_ and _theory marks_. From the main class, create an array of such students. Show their specific information, along with average percentage of marks.
+]
+
+#scos("StudentsArray", pad: 3em)
+
+=== Discussion
+
+#skind[Classes, and methods used from Java standard library]
+
+- `java.util.Scanner` class:
+  - `long nextLong()`: Scan a `long` value from the input stream.
+  - `String nextLine()`: Scan a line of text from the input stream.
+  - `int nextInt()`: Scan an `int` value from the input stream.
+
+#skind[Classes and methods implemented in the program]
+
+- The `Subject` class represents a subject with a title and theory marks.
+  - Constructor `Subject(String, int)`: Create a subject with the given title and theory marks.
+  - `static Subject input(Scanner)`: Takes input for subject details from the user.
+  - `int getTheoryMarks()`: Returns the theory marks for the subject.
+  - `void display()`: Display the marks obtained in the subject.
+
+- The `Student` class represents a student with a roll number, name, stream, and an array of subjects.
+  - Constructor `Student(long, String, String, Subject[])`: Create a student with the given details.
+  - `static Student input(Scanner)`: Takes input for student details from the user.
+  - `void display()`: Display the student details, including roll number, name, stream, subject details, and average percentage.
+
+- The `StudentsArray` class contains the main program to take input for multiple students and display their details:
+  - `public static void main(String[])`: Takes the number of students, inputs details for each student, and displays their details including average percentage.
+
+  
+#signature()
diff --git a/java/text/Template.typ b/java/text/Template.typ
new file mode 100644
index 0000000..d72ff21
--- /dev/null
+++ b/java/text/Template.typ
@@ -0,0 +1,20 @@
+#import "/template.typ": *
+#show: A => apply(A)
+#set raw(lang: "java-new")
+#set par(leading: 0.7em)
+
+#assignment()[
+
+]
+
+#scos("")
+
+=== Discussion
+
+#skind[Classes, interfaces and methods used from Java standard library]
+
+
+#skind[Classes and methods implemented in the program]
+
+  
+#signature()