SortedDictionary.TryGetValue メソッドとは？ わかりやすく解説

Public Function TryGetValue ( _
    key As TKey, _
    <OutAttribute> ByRef value As TValue
 _
) As Boolean

Dim instance As SortedDictionary(Of
 TKey, TValue)
Dim key As TKey
Dim value As TValue
Dim returnValue As Boolean

returnValue = instance.TryGetValue(key, value)

public bool TryGetValue (
    TKey key,
    out TValue value
)

public:
virtual bool TryGetValue (
    TKey key, 
    [OutAttribute] TValue% value
) sealed

public final boolean TryGetValue (
    TKey key, 
    /** @attribute OutAttribute() */ /** @ref */ TValue value
)

JScript では、値型の引数は参照渡しされません。

        ' When a program often has to try keys that turn out not to
        ' be in the dictionary, TryGetValue can be a more efficient
 
        ' way to retrieve values.
        Dim value As String
 = ""
        If openWith.TryGetValue("tif",
 value) Then
            Console.WriteLine("For key = ""tif"",
 value = {0}.", value)
        Else
            Console.WriteLine("Key = ""tif""
 is not found.")
        End If
<br /><span space="preserve">...</span><br
 />        ' The default Item property throws an exception if the
 requested
        ' key is not in the dictionary.
        Try
            Console.WriteLine("For key = ""tif"",
 value = {0}.", _
                openWith("tif"))
        Catch 
            Console.WriteLine("Key = ""tif""
 is not found.")
        End Try

        // When a program often has to try keys that turn out not to
        // be in the dictionary, 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.");
        }
<br /><span space="preserve">...</span><br /> 
       // The indexer throws an exception if the requested key is
        // not in the dictionary.
        try
        {
            Console.WriteLine("For key = \"tif\", value = {0}.",
 
                openWith["tif"]);
        }
        catch (KeyNotFoundException)
        {
            Console.WriteLine("Key = \"tif\" is not found.");
        }