step by step crud operation in motoko - how to store and retrieve data

motoko

type Option = Text;
type Question = {
    questionText : Text;
    options : [Option]; // Array of 4 options
    correctOptionIndex : Nat; // Index 0-3
};

motoko

import Buffer "mo:base/Buffer";
import Array "mo:base/Array";

actor QuestionManager {

    // Define the type for the question
    public type Question = {
        questionText : Text;
        options : [Text]; // Expected size 4
        correctOptionIndex : Nat; // 0, 1, 2, or 3
    };

    // Buffer is a resizable array
    let questionsBuffer = Buffer.Buffer<Question>(10);

    // Function to add a question
    public func addQuestion(q : Question) : async () {
        // Simple validation: Ensure 4 options
        if (q.options.size() == 4) {
            questionsBuffer.add(q);
        };
    };

    // Function to get all questions
    public query func getQuestions() : async [Question] {
        // Convert buffer to immutable array for returning
        return questionsBuffer.toArray();
    };

    // Function to get total question count
    public query func getCount() : async Nat {
        return questionsBuffer.size(); //
    };
}