Records and Modern Types

Deconstruction

Records can be deconstructed into separate variables.

deconstruction Deconstruction splits a value into named local variables.

Deconstruction

right
Deconstruction.cs
Replay: real traced execution (multi-file project)
using System;

record Pair(int Left, int Right)
{
    public override string ToString()
    {
        return Left + ":" + Right;
    }
}

class Program
{
    static void Main()
    {
        int right = 7;
        Pair pair = new Pair(5, right);
        var (left, rightValue) = pair;
        int total = left + rightValue;

        Console.WriteLine($"right={right}");
        Console.WriteLine($"total={total}");
    }
}

using System;

record Pair(int Left, int Right)
{
    public override string ToString()
    {
        return Left + ":" + Right;
    }
}

class Program
{
    static void Main()
    {
        int right = 3;
        Pair pair = new Pair(5, right);
        var (left, rightValue) = pair;
        int total = left + rightValue;

        Console.WriteLine($"right={right}");
        Console.WriteLine($"total={total}");
    }
}

using System;

record Pair(int Left, int Right)
{
    public override string ToString()
    {
        return Left + ":" + Right;
    }
}

class Program
{
    static void Main()
    {
        int right = 10;
        Pair pair = new Pair(5, right);
        var (left, rightValue) = pair;
        int total = left + rightValue;

        Console.WriteLine($"right={right}");
        Console.WriteLine($"total={total}");
    }
}

  1. right ← 7, pair ← 5:7, total ← 12

    12{13    static void Main()14    {15        int right→ 7 = 7; //@right=3, 1016        Pair pair→ 5:7 = new Pair(5, right);17        var (left, rightValue) = pair5:7;18        int total→ 12 = left5 + rightValue7;1920        Console.WriteLine($"right={right7}");21        Console.WriteLine($"total={total12}");22    }
    outputright=7
total=12

  1. right ← 3, pair ← 5:3, total ← 8

    12{13    static void Main()14    {15        int right→ 3 = 3;16        Pair pair→ 5:3 = new Pair(5, right);17        var (left, rightValue) = pair5:3;18        int total→ 8 = left5 + rightValue3;1920        Console.WriteLine($"right={right3}");21        Console.WriteLine($"total={total8}");22    }
    outputright=3
total=8

  1. right ← 10, pair ← 5:10, total ← 15

    12{13    static void Main()14    {15        int right→ 10 = 10;16        Pair pair→ 5:10 = new Pair(5, right);17        var (left, rightValue) = pair5:10;18        int total→ 15 = left5 + rightValue10;1920        Console.WriteLine($"right={right10}");21        Console.WriteLine($"total={total15}");22    }
    outputright=10
total=15