Gets a value from the dictionary with given key. Returns default value if can not find. - CSharp System.Collections.Generic

CSharp examples for System.Collections.Generic:IDictionary

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Description

Gets a value from the dictionary with given key. Returns default value if can not find.

Demo Code


using System.Collections.Generic;

public class Main{
        /// <summary>
        /// Gets a value from the dictionary with given key. Returns default value if can not find.
        /// </summary>
        /// <param name="dictionary">Dictionary to check and get</param>
        /// <param name="key">Key to find the value</param>
        /// <typeparam name="TKey">Type of the key</typeparam>
        /// <typeparam name="TValue">Type of the value</typeparam>
        /// <returns>Value if found, default if can not found.</returns>
        public static TValue GetOrDefault<TKey, TValue>(this IDictionary<TKey, TValue> dictionary, TKey key)
        {/*from   ww w  . j  av  a2  s. c o  m*/
            TValue obj;
            return dictionary.TryGetValue(key, out obj) ? obj : default(TValue);
        }
        /// <summary>
        /// This method is used to try to get a value in a dictionary if it does exists.
        /// </summary>
        /// <typeparam name="T">Type of the value</typeparam>
        /// <param name="dictionary">The collection object</param>
        /// <param name="key">Key</param>
        /// <param name="value">Value of the key (or default value if key not exists)</param>
        /// <returns>True if key does exists in the dictionary</returns>
        internal static bool TryGetValue<T>(this IDictionary<string, object> dictionary, string key, out T value)
        {
            object valueObj;
            if (dictionary.TryGetValue(key, out valueObj) && valueObj is T)
            {
                value = (T)valueObj;
                return true;
            }

            value = default(T);
            return false;
        }
}

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