VB.NET and linQ: How to delete entries from a dictionary using the value
I have a dictionary collection as bleow:
mydic.add开发者_C百科value(key1, val1)
mydic.addvalue(key2, val1)
mydic.addvalue(key3, val1)
mydic.addvalue(key4, val2)
mydic.addvalue(key5, val2)
From the above dictionary I want to delete all the entries where value == "val1", so that the result would have only following entry:
mydic.addvalue(key4, val2)
mydic.addvalue(key5, val2)
My VB source code is on VS2008 and targeted for 3.5
Sub RemoveByValue(Of TKey, TValue)(ByVal dictionary As Dictionary(Of TKey, TValue), ByVal someValue As TValue)
Dim itemsToRemove = (From pair In dictionary _
Where pair.Value.Equals(someValue) _
Select pair.Key).ToArray()
For Each item As TKey In itemsToRemove
dictionary.Remove(item)
Next
End Sub
Usage:
Dim dictionary As New Dictionary(Of Int32, String)
dictionary.Add(1, "foo")
dictionary.Add(2, "foo")
dictionary.Add(3, "bar")
RemoveByValue(dictionary, "foo")
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