Add three Java mini-projects: calculator, inventory manager, and student grader

.gitignore

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+# Compiled class files
+*.class
+
+# Package Files
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# Virtual machine crash logs
+hs_err_pid*
+
+# IDE specific files
+.idea/
+*.iml
+.vscode/
+*.swp
+*.swo
+*~
+
+# OS specific files
+.DS_Store
+Thumbs.db

BasicStdtGrdr/BasicStdtGrdr.java

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+import java.util.ArrayList;
+import java.util.Scanner;
+
+/**
+ * BasicStdtGrdr - Basic Student Grader
+ * 
+ * Features:
+ * - Input student names and five test scores
+ * - Calculates average score for each student
+ * - Assigns letter grade (A-F) based on average
+ * - Outputs formatted results table
+ */
+public class BasicStdtGrdr {
+
+    /**
+     * Main method - Entry point of the application
+     */
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        ArrayList<Student> students = new ArrayList<>();
+
+        try {
+            displayWelcomeMessage();
+
+            // Get number of students
+            System.out.print("Enter number of students: ");
+            int numStudents = scanner.nextInt();
+            scanner.nextLine(); // Clear newline
+
+            // Input data for each student
+            for (int i = 0; i < numStudents; i++) {
+                System.out.println("\n--- Student " + (i + 1) + " ---");
+
+                System.out.print("Enter student name: ");
+                String name = scanner.nextLine();
+
+                double[] scores = new double[5];
+                System.out.println("Enter 5 test scores:");
+
+                boolean validScores = true;
+                for (int j = 0; j < 5; j++) {
+                    System.out.print("Score " + (j + 1) + ": ");
+                    scores[j] = scanner.nextDouble();
+
+                    if (scores[j] < 0 || scores[j] > 100) {
+                        System.out.println("Error: Score must be between 0 and 100! Please re-enter data for this student.");
+                        validScores = false;
+                        break;
+                    }
+                }
+                scanner.nextLine(); // Clear newline
+
+                if (!validScores) {
+                    i--; // Retry this student
+                    continue;
+                }
+
+                Student student = new Student(name, scores);
+                students.add(student);
+            }
+
+            // Display results
+            displayResults(students);
+
+        } catch (Exception e) {
+            System.err.println("Error: Invalid input. Please enter valid data.");
+        } finally {
+            scanner.close();
+        }
+    }
+
+    /**
+     * Displays welcome message
+     */
+    private static void displayWelcomeMessage() {
+        System.out.println("=========================================");
+        System.out.println("     Basic Student Grader System        ");
+        System.out.println("=========================================");
+        System.out.println("This system calculates student averages");
+        System.out.println("and assigns letter grades (A-F).");
+        System.out.println();
+    }
+
+    /**
+     * Displays formatted results table for all students
+     */
+    private static void displayResults(ArrayList<Student> students) {
+        System.out.println("\n\n=========================================");
+        System.out.println("           STUDENT GRADE REPORT          ");
+        System.out.println("=========================================");
+
+        // Table header
+        System.out.printf("%-20s %-8s %-8s %-8s %-8s %-8s %-10s %-6s%n",
+            "Name", "Score1", "Score2", "Score3", "Score4", "Score5", "Average", "Grade");
+        System.out.println("=========================================================================================================");
+
+        // Print each student's data
+        for (Student student : students) {
+            double[] scores = student.getScores();
+            System.out.printf("%-20s %-8.1f %-8.1f %-8.1f %-8.1f %-8.1f %-10.2f %-6s%n",
+                student.getName(),
+                scores[0], scores[1], scores[2], scores[3], scores[4],
+                student.getAverage(),
+                student.getLetterGrade());
+        }
+
+        System.out.println("=========================================================================================================");
+
+        // Display statistics
+        displayStatistics(students);
+    }
+
+    /**
+     * Displays class statistics
+     */
+    private static void displayStatistics(ArrayList<Student> students) {
+        if (students.isEmpty()) {
+            return;
+        }
+
+        double classTotal = 0;
+        double highest = students.get(0).getAverage();
+        double lowest = students.get(0).getAverage();
+
+        for (Student student : students) {
+            double avg = student.getAverage();
+            classTotal += avg;
+            if (avg > highest) highest = avg;
+            if (avg < lowest) lowest = avg;
+        }
+
+        double classAverage = classTotal / students.size();
+
+        System.out.println("\nClass Statistics:");
+        System.out.printf("Class Average: %.2f%n", classAverage);
+        System.out.printf("Highest Average: %.2f%n", highest);
+        System.out.printf("Lowest Average: %.2f%n", lowest);
+        System.out.println("=========================================");
+    }
+}
+
+/**
+ * Student class - Represents a student with scores and grade information
+ */
+class Student {
+    private String name;
+    private double[] scores;
+    private double average;
+    private String letterGrade;
+
+    /**
+     * Constructor to create a new student
+     */
+    public Student(String name, double[] scores) {
+        this.name = name;
+        this.scores = scores;
+        this.average = calculateAverage();
+        this.letterGrade = calculateLetterGrade();
+    }
+
+    /**
+     * Calculates the average of the five scores
+     */
+    private double calculateAverage() {
+        double sum = 0;
+        for (double score : scores) {
+            sum += score;
+        }
+        return sum / scores.length;
+    }
+
+    /**
+     * Determines the letter grade based on average
+     * A: 90-100
+     * B: 80-89
+     * C: 70-79
+     * D: 60-69
+     * F: Below 60
+     */
+    private String calculateLetterGrade() {
+        if (average >= 90) {
+            return "A";
+        } else if (average >= 80) {
+            return "B";
+        } else if (average >= 70) {
+            return "C";
+        } else if (average >= 60) {
+            return "D";
+        } else {
+            return "F";
+        }
+    }
+
+    // Getters
+    public String getName() {
+        return name;
+    }
+
+    public double[] getScores() {
+        return scores;
+    }
+
+    public double getAverage() {
+        return average;
+    }
+
+    public String getLetterGrade() {
+        return letterGrade;
+    }
+}

BasicStdtGrdr/README.md

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+# BasicStdtGrdr (Basic Student Grader)
+
+A student grading system that calculates averages and assigns letter grades.
+
+## Features
+- Input student names and five test scores
+- Automatically calculates average for each student
+- Assigns letter grades (A-F) based on average
+- Displays formatted results table
+- Shows class statistics (class average, highest, lowest)
+
+## Grading Scale
+- **A**: 90-100
+- **B**: 80-89
+- **C**: 70-79
+- **D**: 60-69
+- **F**: Below 60
+
+## How to Compile
+```bash
+javac BasicStdtGrdr.java
+```
+
+## How to Run
+```bash
+java BasicStdtGrdr
+```
+
+## Usage Example
+```
+Enter number of students: 2
+--- Student 1 ---
+Enter student name: John Doe
+Enter 5 test scores:
+Score 1: 95
+Score 2: 88
+Score 3: 92
+Score 4: 85
+Score 5: 90
+
+--- Student 2 ---
+Enter student name: Jane Smith
+Enter 5 test scores:
+Score 1: 78
+Score 2: 82
+Score 3: 75
+Score 4: 80
+Score 5: 85
+```
+
+## Output
+The program displays a formatted table showing:
+- Student names
+- All five scores
+- Calculated average
+- Letter grade
+- Class statistics

README.md

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-# java-Projects
+# Java Mini-Projects Collection
+
+This repository contains three Java mini-projects, each demonstrating fundamental programming concepts.
+
+## Projects Overview
+
+### 1. SimpleCalculator
+A command-line calculator that performs basic arithmetic operations.
+- **Location**: `SimpleCalculator/`
+- **Features**: Addition, subtraction, multiplication, division with error handling
+- **Key Concepts**: Switch statements, exception handling, user input
+- **Lines of Code**: 127
+
+[View SimpleCalculator Documentation](SimpleCalculator/README.md)
+
+### 2. SimpleInventoryManager
+A menu-driven inventory management system.
+- **Location**: `SimpleInventoryManager/`
+- **Features**: Add, view, update, and remove inventory items
+- **Key Concepts**: Java Collections (ArrayList), object-oriented programming, menu-driven interface
+- **Lines of Code**: 226
+
+[View SimpleInventoryManager Documentation](SimpleInventoryManager/README.md)
+
+### 3. BasicStdtGrdr (Basic Student Grader)
+A student grading system with average calculation and letter grade assignment.
+- **Location**: `BasicStdtGrdr/`
+- **Features**: Student data input, average calculation, grade assignment, formatted output
+- **Key Concepts**: Arrays, calculations, formatting, data structures
+- **Lines of Code**: 198
+
+[View BasicStdtGrdr Documentation](BasicStdtGrdr/README.md)
+
+## How to Use
+
+Each project is self-contained in its own directory. To compile and run any project:
+
+```bash
+cd <ProjectDirectory>
+javac <ProjectName>.java
+java <ProjectName>
+```
+
+For example, to run the SimpleCalculator:
+```bash
+cd SimpleCalculator
+javac SimpleCalculator.java
+java SimpleCalculator
+```
+
+## Requirements
+- Java Development Kit (JDK) 8 or higher
+- Command-line interface (Terminal/Command Prompt)
+
+## Project Structure
+```
+java-Projects/
+├── README.md
+├── SimpleCalculator/
+│   ├── SimpleCalculator.java
+│   └── README.md
+├── SimpleInventoryManager/
+│   ├── SimpleInventoryManager.java
+│   └── README.md
+└── BasicStdtGrdr/
+    ├── BasicStdtGrdr.java
+    └── README.md
+```