使用Linq添加或更新字典元素

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        Dictionary<string, int> dictionary = new Dictionary<string, int>();
        string key = "key";
        int value = 10;

        // 使用Linq添加或更新字典元素
        dictionary[key] = dictionary.ContainsKey(key) ? value : dictionary[key] = value;

        // 打印字典中的元素
        foreach (var kvp in dictionary)
        {
            Console.WriteLine($"Key: {kvp.Key}, Value: {kvp.Value}");
        }
    }
}