C# 泛型列表类型管理数据集合

1.列表创建

var names = new List<string> { "博客园", "cc", "efun" ,"zp"}; 
foreach (var name in names)
{
Console.WriteLine($"Hello {name.ToUpper()}!");
}

 

Hello 博客园!
Hello CC!
Hello EFUN!
Hello ZP!

2.列表修改

Console.WriteLine();
names.Add("20201122");     //添加20201122
names.Add("Bill");      //添加Bill
names.Remove("博客园");   //移除博客园
foreach (var name in names)
{
Console.WriteLine($"Hello {name.ToUpper()}!");
}

Hello CC!
Hello EFUN!
Hello ZP!
Hello 20201122!
Hello BILL!

Console.WriteLine($"My name is {names[0]}.");    //names中第一个元素为cc
Console.WriteLine($"I've added {names[names.Count-2]} and {names[names.Count-1]} to the list.");

My name is cc.
I've added 20201122 and Bill to the list.

var index = names.IndexOf("zp");
if (index != -1)
    Console.WriteLine($"The name {names[index]} is at index {index}");
var notFound = names.IndexOf("Not Found");
if(notFound == -1)
    Console.WriteLine($"When an item is not found, IndexOf returns {notFound}");

The name zp is at index 2
When an item is not found, IndexOf returns -1

 

names.Add("幸福");
names.Remove("Bill");
names.Add("echo");
names.Sort(); //排序顺序，先数字后字母，最后汉字
foreach (var name in names)
{
Console.Write($"{name.ToUpper()} ");
}

 

20201122 CC ECHO EFUN ZP 幸福 

3.其他

int CalFibonacciNumber(int index)
{
    var fibonacciNumbers = new List<int> {1, 1};
    for(int i =0;i<index-2;i++)
    {
        var previous = fibonacciNumbers[fibonacciNumbers.Count - 1];
        var previous2 = fibonacciNumbers[fibonacciNumbers.Count - 2];
        fibonacciNumbers.Add(previous + previous2);
    }
    return fibonacciNumbers[index-1];
}
int indexFib = 30;
Console.WriteLine($"第 {indexFib} 个斐波纳契数={CalFibonacciNumber(indexFib)}");

第 30 个斐波纳契数=832040