C#中的字典类
C#中的字典是键和值的集合。它是System.Collection.Generics命名空间中的通用集合类。
语法
以下是语法-
public class Dictionary<TKey,TValue>
上面的key参数是字典中键的类型，而TValue是值的类型。
示例
现在让我们创建一个Dictionary并添加一些元素-
using System;
using System.Collections.Generic;
public class Demo {
public static void Main(){
Dictionary<string, string> dict = new Dictionary<string, string>();
dict.Add("One", "John");
dict.Add("Two", "Tom");
dict.Add("Three", "Jacob");
dict.Add("Four", "Kevin");
dict.Add("Five", "Nathan");
Console.WriteLine("Key/value pairs...");
foreach(KeyValuePair<string, string> res in dict){
Console.WriteLine("Key = {0}, Value = {1}", res.Key, res.Value);
}
}
}输出结果
这将产生以下输出-
Key/value pairs... Key = One, Value = John Key = Two, Value = Tom Key = Three, Value = Jacob Key = Four, Value = Kevin Key = Five, Value = Nathan
示例
现在，让我们看一个示例并删除一些键-
using System;
using System.Collections.Generic;
public class Demo {
public static void Main(){
Dictionary<string, string> dict = new Dictionary<string, string>();
dict.Add("One", "Kagido");
dict.Add("Two", "Ngidi");
dict.Add("Three", "Devillers");
dict.Add("Four", "Smith");
dict.Add("Five", "Warner");
Console.WriteLine("Count of elements = "+dict.Count);
Console.WriteLine("Removing some keys...");
dict.Remove("Four");
dict.Remove("Five");
Console.WriteLine("Count of elements (updated) = "+dict.Count);
Console.WriteLine("\nKey/value pairs...");
foreach(KeyValuePair<string, string> res in dict){
Console.WriteLine("Key = {0}, Value = {1}", res.Key, res.Value);
}
Console.Write("\nAll the keys..\n");
Dictionary<string, string>.KeyCollection allKeys = dict.Keys;
foreach(string str in allKeys){
Console.WriteLine("Key = {0}", str);
}
}
}输出结果
这将产生以下输出-
Count of elements = 5 Removing some keys... Count of elements (updated) = 3 Key/value pairs... Key = One, Value = Kagido Key = Two, Value = Ngidi Key = Three, Value = Devillers All the keys.. Key = One Key = Two Key = Three