c#相当于JavaScript扩展运算符

没有价差期权。这是有原因的。

1. 属性不是C中的数组,除非使用params关键字
2. 使用param关键字的属性必须:
   1. 共享同一类型
   2. 有一个可转换的共享类型,例如用于数字的double
   3. 类型为object[](因为object是所有事物的根类型)

但是,尽管如此,您可以通过各种语言特性获得类似的功能。

回答你的例子:

C#

var arr = new []{
   "1",
   "2"//...
};

Console.WriteLine(string.Join(", ", arr));

您提供的链接有以下示例:

Javascript扩展

function sum(x, y, z) {
  return x + y + z;
}

const numbers = [1, 2, 3];

console.log(sum(...numbers));
// expected output: 6

console.log(sum.apply(null, numbers));

参数 在C#中,同一类型

public int Sum(params int[] values)
{
     return values.Sum(); // Using linq here shows part of why this doesn't make sense.
}

var numbers = new int[] {1,2,3};

Console.WriteLine(Sum(numbers));

在C#中,使用不同的数字类型,使用double

public int Sum(params double[] values)
{
     return values.Sum(); // Using linq here shows part of why this doesn't make sense.
}

var numbers = new double[] {1.5, 2.0, 3.0}; // Double usually doesn't have precision issues with small whole numbers

Console.WriteLine(Sum(numbers));

反思

using System;
using System.Reflection;

namespace ReflectionExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var paramSet = new object[] { 1, 2.0, 3L };
            var mi = typeof(Program).GetMethod("Sum", BindingFlags.Public | BindingFlags.Static);
            Console.WriteLine(mi.Invoke(null, paramSet));
        }

        public static int Sum(int x, double y, long z)
        {
            return x + (int)y + (int)z;
        }
    }
}

获得类似行为的一个诀窍是接受 params SomeObject[][] 以及定义隐式运算符 SomeObject 到 SomeObject[] . 现在可以传递 某物 和个人 某物 元素。

public class Item
{
    public string Text { get; }

    public Item (string text)
    {
        this.Text = text;
    }

    public static implicit operator Item[] (Item one) => new[] { one };
}

public class Print
{
    // Accept a params of arrays of items (but also single items because of implicit cast)

    public static void WriteLine(params Item[][] items)
    {
        Console.WriteLine(string.Join(", ", items.SelectMany(x => x)));
    }
}

public class Test
{
    public void Main()
    {
        var array = new[] { new Item("a1"), new Item("a2"), new Item("a3") };
        Print.WriteLine(new Item("one"), /* ... */ array, new Item("two")); 
    }
}

C中没有直接的预建库来处理Spread中内置的内容

你会做一些类似的事情:

var tempMethods = typeof(myClass).GetMethods();
var tempFields = typeof(myClass).GetFields();
var tempProperties = typeof(myClass).GetProperties();

然后迭代并将其放入动态对象中:

using System;
using System.Collections.Generic;
using System.Dynamic;

namespace myApp
{
    public class myClass
    {
        public string myProp { get; set; }
        public string myField;
        public string myFunction()
        {
            return "";
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            var fields = typeof(myClass).GetFields();
            dynamic EO = new ExpandoObject();
            foreach (int i = 0; i < fields.Length; i++)
            {
                AddProperty(EO, "Language", "lang" + i);
                Console.Write(EO.Language);
            }
        }

        public static void AddProperty(ExpandoObject expando, string propertyName, object propertyValue)
        {
            // ExpandoObject supports IDictionary so we can extend it like this
            var expandoDict = expando as IDictionary<string, object>;
            if (expandoDict.ContainsKey(propertyName))
                expandoDict[propertyName] = propertyValue;
            else
                expandoDict.Add(propertyName, propertyValue);
        }
    }
} 

https://www.oreilly.com/learning/building-c-objects-dynamically

您也可以执行以下操作

    var a  = new List<int>(new int[]{1,2,3}){5};
    Console.WriteLine(a.Count);

将打印4