Primary Constructors in C# 12

As we bid farewell to the older syntax, let’s embrace the newer, more expressive way of creating objects.

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Introduction

In C# 12, primary constructors play a crucial role in defining the behaviour of classes and structs. By adding parameters to a struct or class declaration, you can create a primary constructor.

Use Cases

1. Base Constructor Invocation: Pass primary constructor parameters as arguments to a base constructor invocation. This allows for seamless initialization of base class properties.
2. Member Field Initialization: Primary constructor parameters are often used to initialize member fields or properties. By directly assigning values during construction.

Getting Started

The struct & constructor declaration before C# 12. Please find below the example of the older syntax.

public readonly struct Distance
{
    public readonly double Magnitude { get; }

    public readonly double Direction { get; }

    public Distance(double dx, double dy)
    {
        Magnitude = Math.Sqrt(dx * dx + dy * dy);
        Direction = Math.Atan2(dy, dx);
    }
}

Newer Syntax