在列表 C# 中添加范围的最快方法

Question

I have to add about 3000 Elements to more than 20 Lists. The code that I am using:

LastChange = new List<string>();
LastChange.AddRange(Enumerable.Repeat("/", 3000));

same for more than 20 Lists...

Is there any "fastest way" to add "/" to the Lists or that is the best solution. Thanks in Advance...

Answer 1

A bit better solution is to allocate memory for 3000 items in the constructor in order to avoid memory reallocation:

 LastChange = new List<string>(3000);

 LastChange.AddRange(Enumerable.Repeat("/", 3000)); 

You can go further and get rid of IEnumerator<T> in Enumerable.Repeat :

 int count = 3000;

 LastChange = new List<string>(count);

 // compare to 0 is a bit faster then 3000
 for (int i = count - 1; i >= 0; --i)
   LastChange[i] = "\";