Code readability is enhanced with C# 10 top-level statements

Overview

Introducing top-level statements in C# 10, which provide a more concise, readable entry point to our applications. We'll explore how top-level statements improve code readability in this article.

using System;

// Top-level statements allow for a concise entry point
Console.WriteLine("Hello I am Ziggy Rafiq!");

Understanding Top-Level Statements

The top-level statements of C# 10 eliminate the need to write a Main method as the entry point for our application. This allows us to write executable code at the top level of our application.

using System;

// No need for a Main method
// We can write executable code at the top level

Console.WriteLine("Welcome to C# 10 Top-Level Statements!");

int sum = AddNumbers(5, 7);
Console.WriteLine($"The sum of 5 and 7 is: {sum}");

// Define functions at the top level
int AddNumbers(int a, int b) => a + b;

Embracing the Simplicity

Basic Syntax

Here is a simple example to illustrate the basic syntax of top-level statements. In the code example below, there is no explicit Main method. The application entry point is the top-level statement itself. This simplicity makes the code cleaner and more accessible.

// C# 10 top-level statement
using System;

Console.WriteLine("Hello, C# 10 Top-Level Statements!");

Utilizing Variables

Top-level statements allow us to declare and use variables without the need for an enclosing method. In the code example below, the variables greeting and name are declared at the top level, contributing to a more streamlined and readable code structure.

// C# 10 top-level statement with variables
string greeting = "Hello";
string name = "Ziggy";

Console.WriteLine($"{greeting}, {name}!");

Simplifying Control Flow

Top-level statements extend their simplicity to control flow constructs, such as if statements. In the code example below the absence of an explicit method definition for control flow enhances the clarity of our code.

// C# 10 top-level statement with control flow
bool isEvening = DateTime.Now.Hour >= 18;

if (isEvening)
{
    Console.WriteLine("Good evening!");
}
else
{
    Console.WriteLine("Hello!");
}

Benefits of Top-Level Statements
 

Improved Readability

Top-level statements make the entry point of our application more visible and less cluttered. Developers can quickly understand the core logic without navigating through a traditional Main method.

In this code example below, Using top-level statements instead of a traditional Main method makes the core logic of the application easier to see and less cluttered. The ShowWelcomeMessage function and the addition of numbers are directly expressed, making the code more readable.

using System;

// No need for a Main method, improving readability

ShowWelcomeMessage();

int result = AddNumbers(10, 15);
Console.WriteLine($"The result is: {result}");

// Functions can be defined at the top level
void ShowWelcomeMessage()
{
    Console.WriteLine("Welcome to C# 10 Top-Level Statements!");
}

int AddNumbers(int a, int b) => a + b;

Conciseness

By eliminating the need for explicit method definitions, top-level statements reduce boilerplate code, making our codebase more concise and focused.

In this code example below, the function definition for adding numbers is concise and directly at the top level. Top-level statements reduce boilerplate code, resulting in a more focused and compact codebase.

using System;

// No explicit Main method or method definitions required

Console.WriteLine("C# 10 brings conciseness with top-level statements!");

int result = AddNumbers(8, 12);
Console.WriteLine($"The sum is: {result}");

// Function definition is concise at the top level
int AddNumbers(int a, int b) => a + b;

Enhanced Interactive Development

Top-level statements facilitate interactive development and exploration, allowing developers to experiment with code snippets without the constraints of a formal method structure.

In the code example below, top-level statements enhance interactive development. The Square function is defined and tested interactively, allowing developers to explore and experiment with code more flexibly without a formal method structure. The Square function can be used to experiment with code directly without requiring a formal method structure.

using System;

// Enhanced interactive development with top-level statements

Console.WriteLine("Interactive C# 10 development!");

var number = 42;

// We can experiment with code snippets directly
var squared = Square(number);
Console.WriteLine($"The square of {number} is: {squared}");

// Functions can be defined and tested interactively
int Square(int x) => x * x;

Considerations and Best Practices

While top-level statements provide a simpler syntax, it's essential to consider the following:

Code Organisation

While top-level statements offer brevity, consider the organization of our code, especially for larger projects. It might be beneficial to use top-level statements for small scripts or applications but stick to traditional structures for larger, more complex projects.

Below is an example of how top-level statements are used to implement the main entry point and some simple logic, while larger projects use functions and classes. For smaller scripts or applications, top-level statements can be useful, but for larger, more complex projects, top-level statements can be used to maintain structure.

using System;

// Code organisation with a mix of top-level statements and traditional structure

// Main entry point using top-level statements
Console.WriteLine("C# 10 Code Organization Example");

// Functions and classes for larger projects
int result = CalculateResult();
Console.WriteLine($"The calculated result is: {result}");

// Define a class for a more organized structure
public class Calculator
{
    public int Add(int a, int b) => a + b;
}

// Utilise the class in the traditional structure
int CalculateResult()
{
    var calculator = new Calculator();
    return calculator.Add(10, 20);
}

Error Handling

Be mindful of error handling in top-level statements. For more complex scenarios, a dedicated Main method with proper exception handling may be preferable.

This code example uses a try-catch block to handle potential errors within top-level statements. For more complex error scenarios, a dedicated Main method with proper exception handling is recommended, as demonstrated in this code, instead of top-level statements. In larger applications, this ensures a more structured error-handling approach.

using System;

// Error handling with top-level statements

// Main entry point using top-level statements
try
{
    Console.WriteLine("C# 10 Error Handling Example");

    // Simulate an error scenario
    int result = DivideNumbers(10, 0);
    Console.WriteLine($"The result of the division is: {result}");
}
catch (Exception ex)
{
    Console.WriteLine($"Error: {ex.Message}");
}

// Function with error handling
int DivideNumbers(int dividend, int divisor)
{
    if (divisor == 0)
    {
        throw new ArgumentException("Cannot divide by zero.");
    }

    return dividend / divisor;
}

Summary

With C# 10 top-level statements, developers are able to express ideas more clearly and concisely in a way that is refreshing for them. If we work on smaller scripts, utilities, or quick experiments, we should take advantage of this feature to streamline our code and increase readability. The use of any language feature should be judiciously based on the context of the project as well as the principles of maintainable and scalable code, as with any other language feature.

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Happy coding with C# 10!