Prinsip Pembangunan

Pengaturcaraan ialah satu perjalanan penambahbaikan berterusan. Apabila kami memperoleh pengalaman, kami menghadapi amalan dan prinsip yang membantu kami memperhalusi kraf kami, yang membawa kepada kod yang lebih berkualiti. Artikel ini akan membimbing anda melalui prinsip dan amalan utama yang boleh membantu anda menjadi pengaturcara yang lebih baik, termasuk prinsip SOLID, corak reka bentuk dan piawaian pengekodan. Kami akan meneroka cara konsep ini boleh meningkatkan proses pembangunan anda.

Nota tentang contoh: Saya telah memilih Pergi untuk contoh kod kerana kesederhanaan dan kebolehbacaannya – ia sering digambarkan sebagai "pseudokod boleh laku." Jika anda tidak biasa dengan Go, jangan risau! Ini adalah peluang terbaik untuk belajar.

Apabila anda menemui sintaks atau konsep yang tidak dikenali, luangkan masa untuk mencarinya. Proses penemuan ini boleh menjadi bonus yang menyeronokkan kepada pengalaman pembelajaran anda. Ingat, prinsip yang kita bincangkan terpakai merentas bahasa pengaturcaraan, jadi fokus pada memahami konsep dan bukannya spesifik sintaks Go.

1. Hayati Standard Pengaturcaraan

Salah satu langkah pertama untuk menjadi pengaturcara yang lebih baik ialah mematuhi piawaian pengaturcaraan. Piawaian menyediakan garis panduan untuk aspek seperti konvensyen penamaan, organisasi kod dan struktur fail. Dengan mengikuti konvensyen ini, anda memastikan kod anda konsisten dan mudah dibaca, yang penting untuk kerjasama dan penyelenggaraan jangka panjang.

Setiap bahasa pengaturcaraan biasanya mempunyai set konvensyen tersendiri. Untuk Go, ini digariskan dalam panduan gaya Go rasmi. Adalah penting untuk mempelajari dan menerima piawaian yang berkaitan dengan konteks anda, sama ada konvensyen pasukan anda atau garis panduan khusus bahasa.

Mari kita lihat contoh bagaimana piawaian berikut boleh meningkatkan kebolehbacaan kod:

// Before: Inconsistent styling
func dosomething(x int,y string)string{
if x>10{
return y+"is big"
}else{
return y+"is small"
}}

Kod ini mempunyai beberapa isu:

1. Jarak dan lekukan yang tidak konsisten menyukarkan untuk memahami struktur kod.
2. Nama fungsi tidak mengikut konvensyen camelCase Go.
3. Klausa lain yang tidak perlu menambah kerumitan kognitif.

Sekarang, mari kita memfaktorkan semula kod ini untuk mengikut piawaian Go:

// After: Following Go standards
func doSomething(x int, y string) string {
    if x > 10 {
        return y + " is big"
    }
    return y + " is small"
}

Dalam versi yang dipertingkatkan ini:

1. Lekukan yang betul jelas menunjukkan struktur kod.
2. Nama fungsi mengikut konvensyen penamaan Go.
3. Klausa lain dialih keluar, memudahkan logik.

Perubahan ini bukan hanya mengenai estetika; mereka meningkatkan kebolehbacaan dan kebolehselenggaraan kod dengan ketara. Apabila bekerja dalam satu pasukan, penggunaan piawaian ini secara konsisten memudahkan semua orang memahami dan bekerja dengan pangkalan kod.

Walaupun pasukan anda tidak mempunyai piawaian yang ditetapkan, anda boleh mengambil inisiatif untuk mengikuti konvensyen yang diterima secara meluas dalam komuniti pengaturcaraan. Lama kelamaan, amalan ini akan membawa kepada kod yang lebih mudah dibaca dan boleh diselenggara merentas projek anda.

2. Ikut Prinsip Reka Bentuk

Prinsip reka bentuk pengaturcaraan ialah garis panduan yang membantu anda menulis kod yang lebih baik. Prinsip ini boleh digunakan bukan sahaja untuk seni bina kod tetapi juga untuk reka bentuk sistem dan juga beberapa aspek proses pembangunan.
Terdapat banyak prinsip reka bentuk, dan beberapa lebih relevan dalam konteks tertentu. Yang lain lebih umum seperti KISS (Keep It Simple, Stupid) atau YAGNI (You Ain't Gonna Need It).
Antara prinsip am ini, prinsip SOLID adalah antara yang paling berkesan. Mari kita terokai setiap prinsip dengan memfokuskan pada cara ia boleh meningkatkan kod anda.

Prinsip Tanggungjawab Tunggal (SRP)

Prinsip ini menggalakkan anda mereka bentuk komponen (fungsi, kelas atau modul) dengan satu tujuan yang jelas. Apabila komponen mempunyai pelbagai tanggungjawab, ia menjadi lebih sukar untuk difahami, diuji dan diselenggara.

Mari kita lihat contoh pemfaktoran semula fungsi untuk mematuhi SRP:

// Before: A function doing too much
func processOrder(order Order) error {
    // Validate order
    if order.Total <= 0 {
        return errors.New("invalid order total")
    }
    // Save to database
    db.Save(order)
    // Send confirmation email
    sendEmail(order.CustomerEmail, "Order Confirmation", orderDetails(order))
    // Update inventory
    for _, item := range order.Items {
        updateInventory(item.ID, item.Quantity)
    }
    return nil
}

Fungsi ini melakukan pelbagai tugas yang tidak berkaitan: mengesahkan pesanan, menyimpannya ke pangkalan data, menghantar e-mel dan mengemas kini inventori. Mari pecahkannya kepada fungsi yang berasingan, masing-masing dengan satu tanggungjawab:

// After: Breaking it down into single responsibilities
func processOrder(order Order) error {
    if err := validateOrder(order); err != nil {
        return err
    }
    if err := saveOrder(order); err != nil {
        return err
    }
    if err := sendOrderConfirmation(order); err != nil {
        return err
    }
    return updateInventoryForOrder(order)
}

Sekarang, mari kita laksanakan setiap fungsi ini:

func validateOrder(order Order) error {
    if order.Total <= 0 {
        return errors.New("invalid order total")
    }
    return nil
}

func saveOrder(order Order) error {
    return db.Save(order)
}

func sendOrderConfirmation(order Order) error {
    return sendEmail(order.CustomerEmail, "Order Confirmation", orderDetails(order))
}

func updateInventoryForOrder(order Order) error {
    for _, item := range order.Items {
        if err := updateInventory(item.ID, item.Quantity); err != nil {
            return err
        }
    }
    return nil
}

Dalam versi pemfaktoran semula ini:

• Setiap fungsi mempunyai satu tanggungjawab yang jelas.
• Kod lebih modular dan lebih mudah untuk diuji.
• Komponen individu boleh digunakan semula atau diubah suai tanpa menjejaskan orang lain.

Percayalah, diri masa depan anda akan berterima kasih atas tahap organisasi ini.

Prinsip Terbuka-Tertutup (OCP)

Prinsip Terbuka-Tertutup menasihatkan bahawa entiti perisian harus dibuka untuk sambungan tetapi ditutup untuk pengubahsuaian. Ini bermakna anda sepatutnya boleh menambah fungsi baharu tanpa menukar kod sedia ada.

Liskov Substitution Principle (LSP)

LSP states that objects of a superclass should be replaceable with objects of its subclasses without affecting the correctness of the program. This ensures that inheritance hierarchies are well-designed and maintainable.

Interface Segregation Principle (ISP)

ISP suggests that no code should be forced to depend on methods it does not use. In practice, this often means creating smaller, more focused interfaces.This modularity makes your code easier to manage and test.

Here's an example demonstrating ISP:

// Before: A large interface that many structs only partially implement
type Worker interface {
    DoWork()
    TakeBreak()
    GetPaid()
    FileTicket()
}

This large interface forces implementers to define methods they might not need. Let's break it down into smaller, more focused interfaces:

// After: Smaller, more focused interfaces
type Worker interface {
    DoWork()
}

type BreakTaker interface {
    TakeBreak()
}

type Payable interface {
    GetPaid()
}

type TicketFiler interface {
    FileTicket()
}

Now, structs can implement only the interfaces they need:

type Developer struct{}

func (d Developer) DoWork() {
    fmt.Println("Writing code")
}

func (d Developer) TakeBreak() {
    fmt.Println("Browsing Reddit")
}

func (d Developer) FileTicket() {
    fmt.Println("Creating a Jira ticket")
}

type Contractor struct{}

func (c Contractor) DoWork() {
    fmt.Println("Completing assigned task")
}

func (c Contractor) GetPaid() {
    fmt.Println("Invoicing for work done")
}

This modularity makes your code easier to manage and test. In Go, interfaces are implicitly implemented, which makes this principle particularly easy to apply.

Dependency Inversion Principle (DIP)

DIP promotes the use of abstractions rather than concrete implementations. By depending on interfaces or abstract classes, you decouple your code, making it more flexible and easier to maintain. This also facilitates easier testing by allowing mock implementations.

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Applying the SOLID (see what I did there?) principles leads to decoupled, modular code that is easier to maintain, scale, reuse, and test. I’ve found that these principles, while sometimes challenging to apply at first, have consistently led to more robust and flexible codebases.

While these principles are valuable, remember that they are guidelines, not strict rules.There will always be exceptions to the rules, but it’s important to remember that following these principles is a continuous process and not a one-time event. It will take time and effort to develop good habits, but the rewards are well worth it.

3. Utilize Design Patterns

Design patterns provide reusable solutions to common programming problems. They are not rigid implementations but rather templates that can be adapted to fit specific needs. Many design patterns are related to SOLID principles, often aiming to uphold one or more of these principles in their design.

Design patterns are typically categorized into three types:

Creational Patterns

These patterns deal with object creation mechanisms. An example is the Factory Method pattern, which creates objects based on a set of criteria while abstracting the instantiation logic.

Let's look at a simple Factory Method example in Go:

type PaymentMethod interface {
    Pay(amount float64) string
}

type CashPayment struct{}

func (c CashPayment) Pay(amount float64) string {
    return fmt.Sprintf("Paid %.2f using cash", amount)
}

type CreditCardPayment struct{}

func (cc CreditCardPayment) Pay(amount float64) string {
    return fmt.Sprintf("Paid %.2f using credit card", amount)
}

Here, we define a PaymentMethod interface and two concrete implementations. Now, let's create a factory function:

func GetPaymentMethod(method string) (PaymentMethod, error) {
    switch method {
    case "cash":
        return CashPayment{}, nil
    case "credit":
        return CreditCardPayment{}, nil
    default:
        return nil, fmt.Errorf("Payment method %s not supported", method)
    }
}

This factory function creates the appropriate payment method based on the input string. Here's how you might use it:

method, err := GetPaymentMethod("cash")
if err != nil {
    fmt.Println(err)
    return
}
fmt.Println(method.Pay(42.42))

This pattern allows for easy extension of payment methods without modifying existing code.

Structural Patterns

Structural patterns deal with object composition, promoting better interaction between classes. The Adapter pattern, for example, allows incompatible interfaces to work together.

Behavioral Patterns

Behavioral patterns focus on communication between objects. The Observer pattern is a common behavioral pattern that facilitates a publish-subscribe model, enabling objects to react to events.

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It's important to note that there are many more design patterns, and some are more relevant in specific contexts. For example, game development might heavily use the Object Pool pattern, while it's less common in web development.

Design patterns help solve recurring problems and create a universal vocabulary among developers. However, don't feel pressured to learn all patterns at once. Instead, familiarize yourself with the concepts, and when facing a new problem, consider reviewing relevant patterns that might offer a solution. Over time, you'll naturally incorporate these patterns into your design process.

4. Practice Good Naming Conventions

Clear naming conventions are crucial for writing readable and maintainable code. This practice is closely related to programming standards and deserves special attention.

Use Descriptive Names

Choose names that clearly describe the purpose of the variable, function, or class. Avoid unnecessary encodings or cryptic abbreviations.

Consider this poorly named function:

// Bad
func calc(a, b int) int {
    return a + b
}

Now, let's improve it with more descriptive names:

// Good
func calculateSum(firstNumber, secondNumber int) int {
    return firstNumber + secondNumber
}

However, be cautious not to go to the extreme with overly long names:

// Too verbose
func calculateSumOfTwoIntegersAndReturnTheResult(firstInteger, secondInteger int) int {
    return firstInteger + secondInteger
}

Balance Clarity and Conciseness

Aim for names that are clear but not overly verbose. Good naming practices make your code self-documenting, reducing the need for excessive comments.

Prefer Good Names to Comments

Often, the need for comments arises from poorly named elements in your code. If you find yourself writing a comment to explain what a piece of code does, consider whether you could rename variables or functions to make the code self-explanatory.

Replace Magic Values with Named Constants

Using named constants instead of hard-coded values clarifies their meaning and helps keep your code consistent.

// Bad
if user.Age >= 18 {
    // Allow access
}

// Good
const LegalAge = 18
if user.Age >= LegalAge {
    // Allow access
}

By following these naming conventions, you'll create code that's easier to read, understand, and maintain.

5. Prioritize Testing

Testing is an essential practice for ensuring that your code behaves as expected. While there are many established opinions on testing methodologies, it's okay to develop an approach that works best for you and your team.

Unit Testing

Unit tests focus on individual modules in isolation. They provide quick feedback on whether specific parts of your code are functioning correctly.

Here's a simple example of a unit test in Go:

func TestCalculateSum(t *testing.T) {
    result := calculateSum(3, 4)
    expected := 7
    if result != expected {
        t.Errorf("calculateSum(3, 4) = %d; want %d", result, expected)
    }
}

Integration Testing

Integration tests examine how different modules work together. They help identify issues that might arise from interactions between various parts of the code.

End-to-End Testing

End-to-end tests simulate user interactions with the entire application. They validate that the system works as a whole, providing a user-centric view of functionality.

Remember, well-tested code is not only more reliable but also easier to refactor and maintain over time. The SOLID principles we discussed earlier can make testing easier by encouraging modular, decoupled code that is simpler to isolate and validate.

6. Take Your Time to Plan and Execute

While it might be tempting to rush through projects, especially when deadlines are tight, thoughtful planning is crucial for long-term success. Rushing can lead to technical debt and future maintenance challenges.

Take the time to carefully consider architectural decisions and plan your approach. Building a solid foundation early on will save time and effort in the long run. However, be cautious not to over-plan—find a balance that works for your project's needs.

Different projects may require varying levels of planning. A small prototype might need minimal upfront design, while a large, complex system could benefit from more extensive planning. The key is to be flexible and adjust your approach based on the project's requirements and constraints.

Conclusion

By following these principles and practices, you can become a better programmer. Focus on writing code that is clear, maintainable, and thoughtfully structured. Remember the words of Martin Fowler: "Any fool can write code that a computer can understand. Good programmers write code that humans can understand."

Becoming a better programmer is a continuous process. Don't be discouraged if you don't get everything right immediately. Keep learning, keep practicing, and most importantly, keep coding. With time and dedication, you'll see significant improvements in your skills and the quality of your work.

Here are some resources you might find helpful for further learning:

• For general programming principles: Programming Principles
• For understanding the importance of basics: The Basics
• For a deep dive into software design: The Philosophy of Software Design and its discussion
• For practical programming advice: The Pragmatic Programmer
• For improving existing code: Refactoring

Now, armed with these principles, start applying them to your projects. Consider creating a small web API that goes beyond simple CRUD operations, or develop a tool that solves a problem you face in your daily work. Remember, the best way to learn is by doing. Happy coding!

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