C# 7.0 Local Functions

C# 7.0 introduced local functions, which are methods defined inside other methods or properties. Local functions are used to modularize code and make it easier to read and maintain.

Syntax

Local functions are declared using the static or async modifier followed by the method's return type and name. The method can then take any number of parameters.

Example:

public void OuterMethod()
{
    void InnerMethod(int x, int y)
    {
        Console.WriteLine(x + y);
    }

    InnerMethod(2, 3);
}

In the example above, OuterMethod contains a local function called InnerMethod that takes two int parameters and prints their sum to the console.

Local functions are only accessible within the method in which they are defined.

Benefits

Improved readability

Local functions make code more readable by grouping related code together. This allows developers to easily understand what a given method is doing, without having to scan through a long list of unrelated methods.

Improved maintainability

Local functions make code more maintainable by reducing code duplication. If the same functionality is needed in multiple places, it can be defined once as a local function and reused throughout the method.

Improved performance

Local functions can improve performance by reducing the need for large, complex methods. This can reduce memory usage and improve code execution times.

Conclusion

Local functions are a powerful feature of C# 7.0 that can greatly improve code readability, maintainability, and performance. They allow developers to modularize code and make it easier to read and maintain.