SortedList<TKey,TValue>.TryGetValue(TKey, TValue) Method

Definition

Gets the value associated with the specified key.

public bool TryGetValue (TKey key, out TValue value);

Parameters

key
TKey

The key whose value to get.

value
TValue

When this method returns, the value associated with the specified key, if the key is found; otherwise, the default value for the type of the value parameter. This parameter is passed uninitialized.

Returns

true if the SortedList<TKey,TValue> contains an element with the specified key; otherwise, false.

Implements

Exceptions

key is null.

Examples

The example shows how to use the TryGetValue method as a more efficient way to retrieve values in a program that frequently tries keys that are not in the sorted list. For contrast, the example also shows how the Item[] property (the indexer in C#) throws exceptions when attempting to retrieve nonexistent keys.

This code example is part of a larger example provided for the SortedList<TKey,TValue> class.

// When a program often has to try keys that turn out not to
// be in the list, TryGetValue can be a more efficient
// way to retrieve values.
string value = "";
if (openWith.TryGetValue("tif", out value))
{
    Console.WriteLine("For key = \"tif\", value = {0}.", value);
}
else
{
    Console.WriteLine("Key = \"tif\" is not found.");
}
// The indexer throws an exception if the requested key is
// not in the list.
try
{
    Console.WriteLine("For key = \"tif\", value = {0}.",
        openWith["tif"]);
}
catch (KeyNotFoundException)
{
    Console.WriteLine("Key = \"tif\" is not found.");
}

Remarks

This method combines the functionality of the ContainsKey method and the Item[] property.

If the key is not found, then the value parameter gets the appropriate default value for the value type TValue; for example, zero (0) for integer types, false for Boolean types, and null for reference types.

This method performs a binary search; therefore, this method is an O(log n) operation, where n is Count.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0

See also