ContainsKey 是 C# 中的 Dictionary 方法,用于检查字典中是否存在键。
声明字典并添加元素 -
var dict = new Dictionary<string, int>() { {"TV", 1}, {"Home Theatre", 2}, {"Amazon Alexa", 3}, {"Google Home", 5}, {"Laptop", 5}, {"Bluetooth Speaker", 6} };
现在,假设您需要检查字典中是否存在特定元素。为此,使用ContainsKey()方法 -
if (dict.ContainsKey("Laptop") == true) { Console.WriteLine(dict["Laptop"]); }
以下是代码 -
using System; using System.Collections.Generic; public class Demo { public static void Main() { var dict = new Dictionary<string, int>() { {"TV", 1}, {"Home Theatre", 2}, {"Amazon Alexa", 3}, {"Google Home", 5}, {"Laptop", 5}, {"Bluetooth Speaker", 6} }; if (dict.ContainsKey("Laptop") == true) { Console.WriteLine(dict["Laptop"]); } if (dict.ContainsKey("Amazon Alexa") == true) { Console.WriteLine(dict["Amazon Alexa"]); } } }输出结果
5 3