fun with Span.cs

/*
  SharpLab tools in Run mode:
    • value.Inspect()
    • Inspect.Heap(object)
    • Inspect.Stack(value)
    • Inspect.MemoryGraph(value1, value2, …)
*/
using System;
using System.Runtime.InteropServices;

class Program{
    
    public static void Main()
    {
        WorkWithSpans();
    }

public static void WorkWithSpans()
{
    // Create a span over an array.
    var array = new byte[100];
    var arraySpan = new Span<byte>(array);

    InitializeSpan(arraySpan);
    Console.WriteLine($"The sum is {ComputeSum(arraySpan):N0}");
    Inspect.Heap(array);

    // Create an array from native memory.
    var native = Marshal.AllocHGlobal(100);
    Span<byte> nativeSpan;
    unsafe
    {
        nativeSpan = new Span<byte>(native.ToPointer(), 100);
    }

    InitializeSpan(nativeSpan);
    Console.WriteLine($"The sum is {ComputeSum(nativeSpan):N0}");

    Marshal.FreeHGlobal(native);

    // Create a span on the stack.
    Span<byte> stackSpan = stackalloc byte[100];

    InitializeSpan(stackSpan);

    Console.WriteLine($"The sum is {ComputeSum(stackSpan):N0}");
}

public static void InitializeSpan(Span<byte> span)
{
    byte value = 0;
    for (int ctr = 0; ctr < span.Length; ctr++)
        span[ctr] = value++;
}

public static int ComputeSum(Span<byte> span)
{
    int sum = 0;
    foreach (var value in span)
        sum += value;

    return sum;
}
}
// The example displays the following output:
//    The sum is 4,950
//    The sum is 4,950
//    The sum is 4,950

​fun with Span.output.txt

The sum is 4,950
{
    "type": "inspection:memory",
    "title": "System.Byte[] at 0x2765CE7D068",
    "labels": [
        {
            "name": "header",
            "offset": 0,
            "length": 8
        },
        {
            "name": "type handle",
            "offset": 8,
            "length": 8
        },
        {
            "name": "length",
            "offset": 16,
            "length": 8
        },
        {
            "name": "0",
            "offset": 24,
            "length": 1
        },
        {
            "name": "1",
            "offset": 25,
            "length": 1
        },
        {
            "name": "2",
            "offset": 26,
            "length": 1
        },
        {
            "name": "3",
            "offset": 27,
            "length": 1
        },
        {
            "name": "4",
            "offset": 28,
            "length": 1
        },
        {
            "name": "5",
            "offset": 29,
            "length": 1
        },
        {
            "name": "6",
            "offset": 30,
            "length": 1
        },
        {
            "name": "7",
            "offset": 31,
            "length": 1
        },
        {
            "name": "8",
            "offset": 32,
            "length": 1
        },
        {
            "name": "9",
            "offset": 33,
            "length": 1
        },
        {
            "name": "10",
            "offset": 34,
            "length": 1
        },
        {
            "name": "11",
            "offset": 35,
            "length": 1
        },
        {
            "name": "12",
            "offset": 36,
            "length": 1
        },
        {
            "name": "13",
            "offset": 37,
            "length": 1
        },
        {
            "name": "14",
            "offset": 38,
            "length": 1
        },
        {
            "name": "15",
            "offset": 39,
            "length": 1
        },
        {
            "name": "16",
            "offset": 40,
            "length": 1
        },
        {
            "name": "17",
            "offset": 41,
            "length": 1
        },
        {
            "name": "18",
            "offset": 42,
            "length": 1
        },
        {
            "name": "19",
            "offset": 43,
            "length": 1
        },
        {
            "name": "20",
            "offset": 44,
            "length": 1
        },
        {
            "name": "21",
            "offset": 45,
            "length": 1
        },
        {
            "name": "22",
            "offset": 46,
            "length": 1
        },
        {
            "name": "23",
            "offset": 47,
            "length": 1
        },
        {
            "name": "24",
            "offset": 48,
            "length": 1
        },
        {
            "name": "25",
            "offset": 49,
            "length": 1
        },
        {
            "name": "26",
            "offset": 50,
            "length": 1
        },
        {
            "name": "27",
            "offset": 51,
            "length": 1
        },
        {
            "name": "28",
            "offset": 52,
            "length": 1
        },
        {
            "name": "29",
            "offset": 53,
            "length": 1
        },
        {
            "name": "30",
            "offset": 54,
            "length": 1
        },
        {
            "name": "31",
            "offset": 55,
            "length": 1
        },
        {
            "name": "32",
            "offset": 56,
            "length": 1
        },
        {
            "name": "33",
            "offset": 57,
            "length": 1
        },
        {
            "name": "34",
            "offset": 58,
            "length": 1
        },
        {
            "name": "35",
            "offset": 59,
            "length": 1
        },
        {
            "name": "36",
            "offset": 60,
            "length": 1
        },
        {
            "name": "37",
            "offset": 61,
            "length": 1
        },
        {
            "name": "38",
            "offset": 62,
            "length": 1
        },
        {
            "name": "39",
            "offset": 63,
            "length": 1
        },
        {
            "name": "40",
            "offset": 64,
            "length": 1
        },
        {
            "name": "41",
            "offset": 65,
            "length": 1
        },
        {
            "name": "42",
            "offset": 66,
            "length": 1
        },
        {
            "name": "43",
            "offset": 67,
            "length": 1
        },
        {
            "name": "44",
            "offset": 68,
            "length": 1
        },
        {
            "name": "45",
            "offset": 69,
            "length": 1
        },
        {
            "name": "46",
            "offset": 70,
            "length": 1
        },
        {
            "name": "47",
            "offset": 71,
            "length": 1
        },
        {
            "name": "48",
            "offset": 72,
            "length": 1
        },
        {
            "name": "49",
            "offset": 73,
            "length": 1
        },
        {
            "name": "50",
            "offset": 74,
            "length": 1
        },
        {
            "name": "51",
            "offset": 75,
            "length": 1
        },
        {
            "name": "52",
            "offset": 76,
            "length": 1
        },
        {
            "name": "53",
            "offset": 77,
            "length": 1
        },
        {
            "name": "54",
            "offset": 78,
            "length": 1
        },
        {
            "name": "55",
            "offset": 79,
            "length": 1
        },
        {
            "name": "56",
            "offset": 80,
            "length": 1
        },
        {
            "name": "57",
            "offset": 81,
            "length": 1
        },
        {
            "name": "58",
            "offset": 82,
            "length": 1
        },
        {
            "name": "59",
            "offset": 83,
            "length": 1
        },
        {
            "name": "60",
            "offset": 84,
            "length": 1
        },
        {
            "name": "61",
            "offset": 85,
            "length": 1
        },
        {
            "name": "62",
            "offset": 86,
            "length": 1
        },
        {
            "name": "63",
            "offset": 87,
            "length": 1
        },
        {
            "name": "64",
            "offset": 88,
            "length": 1
        },
        {
            "name": "65",
            "offset": 89,
            "length": 1
        },
        {
            "name": "66",
            "offset": 90,
            "length": 1
        },
        {
            "name": "67",
            "offset": 91,
            "length": 1
        },
        {
            "name": "68",
            "offset": 92,
            "length": 1
        },
        {
            "name": "69",
            "offset": 93,
            "length": 1
        },
        {
            "name": "70",
            "offset": 94,
            "length": 1
        },
        {
            "name": "71",
            "offset": 95,
            "length": 1
        },
        {
            "name": "72",
            "offset": 96,
            "length": 1
        },
        {
            "name": "73",
            "offset": 97,
            "length": 1
        },
        {
            "name": "74",
            "offset": 98,
            "length": 1
        },
        {
            "name": "75",
            "offset": 99,
            "length": 1
        },
        {
            "name": "76",
            "offset": 100,
            "length": 1
        },
        {
            "name": "77",
            "offset": 101,
            "length": 1
        },
        {
            "name": "78",
            "offset": 102,
            "length": 1
        },
        {
            "name": "79",
            "offset": 103,
            "length": 1
        },
        {
            "name": "80",
            "offset": 104,
            "length": 1
        },
        {
            "name": "81",
            "offset": 105,
            "length": 1
        },
        {
            "name": "82",
            "offset": 106,
            "length": 1
        },
        {
            "name": "83",
            "offset": 107,
            "length": 1
        },
        {
            "name": "84",
            "offset": 108,
            "length": 1
        },
        {
            "name": "85",
            "offset": 109,
            "length": 1
        },
        {
            "name": "86",
            "offset": 110,
            "length": 1
        },
        {
            "name": "87",
            "offset": 111,
            "length": 1
        },
        {
            "name": "88",
            "offset": 112,
            "length": 1
        },
        {
            "name": "89",
            "offset": 113,
            "length": 1
        },
        {
            "name": "90",
            "offset": 114,
            "length": 1
        },
        {
            "name": "91",
            "offset": 115,
            "length": 1
        },
        {
            "name": "92",
            "offset": 116,
            "length": 1
        },
        {
            "name": "93",
            "offset": 117,
            "length": 1
        },
        {
            "name": "94",
            "offset": 118,
            "length": 1
        },
        {
            "name": "95",
            "offset": 119,
            "length": 1
        },
        {
            "name": "96",
            "offset": 120,
            "length": 1
        },
        {
            "name": "97",
            "offset": 121,
            "length": 1
        },
        {
            "name": "98",
            "offset": 122,
            "length": 1
        },
        {
            "name": "99",
            "offset": 123,
            "length": 1
        }
    ],
    "data": [
        0,
        0,
        0,
        0,
        0,
        0,
        0,
        0,
        176,
        141,
        192,
        180,
        249,
        127,
        0,
        0,
        100,
        0,
        0,
        0,
        0,
        0,
        0,
        0,
        0,
        1,
        2,
        3,
        4,
        5,
        6,
        7,
        8,
        9,
        10,
        11,
        12,
        13,
        14,
        15,
        16,
        17,
        18,
        19,
        20,
        21,
        22,
        23,
        24,
        25,
        26,
        27,
        28,
        29,
        30,
        31,
        32,
        33,
        34,
        35,
        36,
        37,
        38,
        39,
        40,
        41,
        42,
        43,
        44,
        45,
        46,
        47,
        48,
        49,
        50,
        51,
        52,
        53,
        54,
        55,
        56,
        57,
        58,
        59,
        60,
        61,
        62,
        63,
        64,
        65,
        66,
        67,
        68,
        69,
        70,
        71,
        72,
        73,
        74,
        75,
        76,
        77,
        78,
        79,
        80,
        81,
        82,
        83,
        84,
        85,
        86,
        87,
        88,
        89,
        90,
        91,
        92,
        93,
        94,
        95,
        96,
        97,
        98,
        99
    ]
}
The sum is 4,950
The sum is 4,950

​​.sharplab.json

{
    "version": 1,
    "target": "Run",
    "mode": "Debug"
}