Saturday, June 9, 2007

Find an element in Array ( .NET )

Most of us will often need to find an element in an array. In C or C++, we can do this by using the FOR loops. In .NET 2.0, we have a build-in method, which is very simple and powerful too. It is similar to ArrayList’s Contains method. The following code snippet will show this.

Private Function MyMethod() as string
Dim countryCodes() As String
countryCodes = “IND,CHI,JPN”.Split(”,”.ToCharArray)
If Array.Exists(countryCodes, AddressOf CountryCodeStartsWith) Then
Return “Exists”
Return “Not Exists”
End If
End Function

Private Function CountryCodeStartsWith(ByVal countryCode As String) As Boolean
dim Country as string = “INDIA”
If Country.startsWith(countryCode) Then
Return True
Return False
End If
End Function

The Array.Exists has two parameters. The first one is nothing but an array where the element is to searched. The second part of the code , which will be confusing for beginners, is a delegate for the function. At the time of execution the elements in CountryCodes - Our Array - will be passed as a parameter to this delegate. also we can customize this matching function very easily.Hope this will help you.

- P

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