python 的 enumerate() 在 C# 中等效吗？

Question

我正在学习 C#，并且参加了很多在线课程。我正在寻找一种更简单/更简洁的方法来枚举列表中的列表。

在 python 中，我们只需一行即可完成类似的操作：

newListofList=[[n,i] for n,i in enumerate([List1,List2,List3])]

C#中一定要涉及lambda和Linq吗？如果是这样，解决办法是什么？我在 C# 中尝试使用 Dictionary，但我的直觉告诉我这不是一个完美的解决方案。

List<List<string>> familyListss = new List<List<string>>();
familyListss.Add(new List<string> { "Mary", "Mary_sister", "Mary_father", "Mary_mother", "Mary_brother" });
familyListss.Add(new List<string> { "Peter", "Peter_sister", "Peter_father", "Peter_mother", "Peter_brother" });
familyListss.Add(new List<string> { "John", "John_sister", "John_father", "John_mother", "John_brother" });

Dictionary<int, List<string>> familyData = new Dictionary<int, List<string>>();

for (int i = 0; i < familyListss.Count; i++)
{
  familyData.Add(i, familyListss[i]);
}

Answer 1

只需一个构造函数就足够了：

List<List<string>> familyListss = new List<List<string>>() {
  new List<string> { "Mary", "Mary_sister", "Mary_father", "Mary_mother", "Mary_brother" },
  new List<string> { "Peter", "Peter_sister", "Peter_father", "Peter_mother", "Peter_brother" },
  new List<string> { "John", "John_sister", "John_father", "John_mother", "John_brother" }
};

如果你想模仿enumerate你可以使用Linq，Select((value, index) => your lambda here)：

using System.Linq;

...

var list = new List<string>() {
  "a", "b", "c", "d"};

var result = list
  .Select((value, index) => $"item[{index}] = {value}");

Console.Write(string.Join(Environment.NewLine, result));

结果：

item[0] = a
item[1] = b
item[2] = c
item[3] = d