C#-এ Dictionary-এ কী (Key) খোঁজা: ContainsKey() মেথড

Dictionary<TKey, TValue>.ContainsKey(key) মেথড নির্দিষ্ট কী ডিকশনারিতে আছে কিনা চেক করে (O(1))।

উদাহরণ

using System;
using System.Collections.Generic;

public class Program
{
    public static void Main()
    {
        Dictionary d = new Dictionary()
        {
            {1, "Electronics"},
            {2, "Clothing"},
            {3, "Toys"},
            {4, "Footwear"},
            {5, "Accessories"}
        };

        foreach (KeyValuePair ele in d)
            Console.WriteLine("Key = {0}, Value = {1}", ele.Key, ele.Value);

        Console.WriteLine("Key 5 exists? " + d.ContainsKey(5));
    }
}

আউটপুট

Key = 1, Value = Electronics
Key = 2, Value = Clothing
Key = 3, Value = Toys
Key = 4, Value = Footwear
Key = 5, Value = Accessories
Key 5 exists? True

TryGetValue ব্যবহার করলে একই সময় কী চেক এবং মান পাওয়া যায় (দক্ষতর)।