Collection.Contains(String) Method
Definition
Important
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Returns a value that indicates whether a Visual Basic Collection
object contains an element with a specific key.
public:
bool Contains(System::String ^ Key);
public bool Contains (string Key);
member this.Contains : string -> bool
Public Function Contains (Key As String) As Boolean
Parameters
- Key
- String
Required. A String
expression that specifies the key for which to search the elements of the collection.
Returns
true
if Visual Basic Collection
object contains an element with a specific key; otherwise, false
.
Examples
Dim customers As New Microsoft.VisualBasic.Collection()
Dim accountNumber As String = "1234"
' Insert code that obtains new customer objects.
' Use the new customer's account number as the key.
customers.Add(newCustomer, accountNumber)
' The preceding statements can be repeated for several customers.
Dim searchNumber As String = "1234"
' Insert code to obtain an account number to search for.
If customers.Contains(searchNumber) Then
MsgBox("The desired customer is in the collection.")
Else
MsgBox("The desired customer is not in the collection.")
End If
If you intend to search the collection for elements using their keys, remember to supply the Key
argument every time you call the Add
method.
Remarks
Contains
returns True
if the collection contains an element with a key exactly matching Key
. Otherwise, Contains
returns False
. Case is ignored when matching key values.
A Visual Basic Collection
can hold some elements that have keys and other elements without keys. This depends on whether the call to the Add method supplies an argument to the optional Key
parameter.