C#中的List数组

Question

I want to have an array of Lists. In c++ I do like:

List<int> a[100];

which is an array of 100 Lists. each list can contain many elements. I don't know how to do this in c#. Can anyone help me?

Answer 1

You do like this:

List<int>[] a = new List<int>[100];

Now you have an array of type List<int> containing 100 null references. You have to create lists and put in the array, for example:

a[0] = new List<int>();

Answer 2

Since no context was given to this question and you are a relatively new user, I want to make sure that you are aware that you can have a list of lists. It's not the same as array of list and you asked specifically for that, but nevertheless:

List<List<int>> myList = new List<List<int>>();

you can initialize them through collection initializers like so:

List<List<int>> myList = new List<List<int>>(){{1,2,3},{4,5,6},{7,8,9}};

Answer 3

simple approach:

        List<int>[] a = new List<int>[100];
        for (int i = 0; i < a.Length; i++)
        {
            a[i] = new List<int>();
        }

or LINQ approach

        var b = Enumerable.Range(0,100).Select((i)=>new List<int>()).ToArray();

Answer 4

我可以建议您使用 linq 在同一行创建和初始化数组：

List<int>[] a = new List<int>[100].Select(item=>new List<int>()).ToArray();

Answer 5

List<int>[]  a = new List<int>[100];

You still would have to allocate each individual list in the array before you can use it though:

for (int i = 0; i < a.Length; i++)
    a[i] = new List<int>();

Answer 6

采用

List<int>[] a = new List<int>[100];

Answer 7

// The letter "t" is usually letter "i"//

    for(t=0;t<x[t];t++)
    {

         printf(" %2d          || %7d \n ",t,x[t]);
    }