**Course Title:** Ruby Programming: From Basics to Advanced Techniques **Section Title:** Data Structures: Arrays, Hashes, and Sets **Topic:** Write a Ruby program that utilizes arrays and hashes for data management.(Lab topic) **Objective:** By the end of this topic, you will be able to create a Ruby program that utilizes arrays and hashes to store and manage data. **Introduction** In real-world applications, data management is crucial for efficient and effective program execution. Ruby provides two essential data structures: arrays and hashes, which can be used to manage data. In this topic, we will explore how to use these data structures to build a simple program. **Lab Topic:** Managing Student Data For this lab topic, we will build a Ruby program that manages student data using arrays and hashes. We will create a program that allows us to store, retrieve, and manipulate student information. **Step 1: Creating the Program** Create a new Ruby file called `student_data_manager.rb`. This file will hold our program. ```ruby # student_data_manager.rb ``` **Step 2: Defining the Student Hash** In our program, we will use a hash to store each student's information. The hash will have the following keys: `name`, `age`, `grade`, and `subject`. Create a new method called `create_student` that returns a new student hash. ```ruby def create_student(name, age, grade, subject) { name: name, age: age, grade: grade, subject: subject } end ``` **Step 3: Storing Students in an Array** We will store all the students in an array. Create a new method called `add_student` that adds a student to the array. ```ruby students = [] def add_student(student) students << student end ``` **Step 4: Displaying Student Information** Create a new method called `display_students` that displays each student's information. ```ruby def display_students students.each do |student| puts "Name: #{student[:name]}" puts "Age: #{student[:age]}" puts "Grade: #{student[:grade]}" puts "Subject: #{student[:subject]}" puts "------------------------" end end ``` **Step 5: Retrieving Student Information** Create a new method called `get_student` that retrieves a student's information by name. ```ruby def get_student(name) students.find { |student| student[:name] == name } end ``` **Step 6: Updating Student Information** Create a new method called `update_student` that updates a student's information. ```ruby def update_student(name, attribute, value) student = get_student(name) student[attribute] = value if student end ``` **Step 7: Deleting Student Information** Create a new method called `delete_student` that deletes a student's information. ```ruby def delete_student(name) students.delete(get_student(name)) end ``` **Step 8: Program Execution** Create a new method called `run` that executes the program. ```ruby def run while true puts "1. Add Student" puts "2. Display Students" puts "3. Get Student" puts "4. Update Student" puts "5. Delete Student" puts "6. Exit" choice = gets.chomp.to_i case choice when 1 puts "Enter student name: " name = gets.chomp puts "Enter student age: " age = gets.chomp.to_i puts "Enter student grade: " grade = gets.chomp puts "Enter student subject: " subject = gets.chomp student = create_student(name, age, grade, subject) add_student(student) puts "Student added successfully!" when 2 display_students when 3 puts "Enter student name: " name = gets.chomp student = get_student(name) if student puts "Name: #{student[:name]}" puts "Age: #{student[:age]}" puts "Grade: #{student[:grade]}" puts "Subject: #{student[:subject]}" else puts "Student not found!" end when 4 puts "Enter student name: " name = gets.chomp puts "Enter attribute to update: " attribute = gets.chomp puts "Enter new value: " value = gets.chomp update_student(name, attribute, value) puts "Student updated successfully!" when 5 puts "Enter student name: " name = gets.chomp delete_student(name) puts "Student deleted successfully!" when 6 puts "Exiting program..." break else puts "Invalid choice. Please choose a valid option." end end end run ``` **Conclusion** In this lab topic, we built a Ruby program that utilizes arrays and hashes to store and manage student data. We created methods to add, display, retrieve, update, and delete student information. This program demonstrates the power of using arrays and hashes in Ruby for efficient data management. **What to Do Next** * Run the program and test its functionality. * Experiment with adding more features to the program. * Research and learn more about Ruby's data structures and how they can be used in real-world applications. **External Resources** * [Ruby Documentation: Arrays](https://ruby-doc.org/core-2.7.0/Array.html) * [Ruby Documentation: Hashes](https://ruby-doc.org/core-2.7.0/Hash.html) **Ask for Help** If you have any questions or need help with this topic, feel free to ask in the comments below. **Next Topic** In the next topic, we will cover "Reading from and writing to files in Ruby." This topic is part of the section "File Handling and Exception Management."