Interaction.Environ Method 
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Returns the string associated with an operating-system environment variable.
Overloads
| Environ(String) | Returns the string associated with an operating-system environment variable. | 
| Environ(Int32) | Returns the string associated with an operating-system environment variable. | 
Environ(String)
- Source:
- Interaction.vb
- Source:
- Interaction.vb
- Source:
- Interaction.vb
- Source:
- Interaction.vb
Returns the string associated with an operating-system environment variable.
public:
 static System::String ^ Environ(System::String ^ Expression);public static string Environ(string? Expression);public static string Environ(string Expression);static member Environ : string -> stringPublic Function Environ (Expression As String) As StringParameters
- Expression
- String
Required. Expression that evaluates either a string containing the name of an environment variable, or an integer corresponding to the numeric order of an environment string in the environment-string table.
Returns
The string associated with an operating-system environment variable.
Exceptions
Expression is missing.
Examples
This example uses the Environ function to supply the entry number and length of the PATH statement from the environment-string table.
Sub tenv()
    Dim envString As String
    Dim found As Boolean = False
    Dim index As Integer = 1
    Dim pathLength As Integer
    Dim message As String
    envString = Environ(index)
    While Not found And (envString <> "")
        If (envString.Substring(0, 5) = "Path=") Then
            found = True
        Else
            index += 1
            envString = Environ(index)
        End If
    End While
    If found Then
        pathLength = Environ("PATH").Length
        message = "PATH entry = " & index & " and length = " & pathLength
    Else
        message = "No PATH environment variable exists."
    End If
    MsgBox(message)
End Sub
Remarks
If Expression contains a string, the Environ function returns the text assigned to the specified environment string - that is, the text following the equal sign (=) in the environment-string table for that environment variable. If the string in Expression cannot be found in the environment-string table, a zero-length string ("") is returned.
If Expression contains an integer, the string occupying that numeric position in the environment-string table is returned. In this case, Environ returns all of the text, including the name of the environment variable. If there is no environment string in the specified position, Environ returns a zero-length string.
Important
The Environ function requires environment permission, which might affect its execution in partial-trust situations. For more information, see SecurityPermission and Code Access Permissions.
See also
Applies to
Environ(Int32)
- Source:
- Interaction.vb
- Source:
- Interaction.vb
- Source:
- Interaction.vb
- Source:
- Interaction.vb
Returns the string associated with an operating-system environment variable.
public:
 static System::String ^ Environ(int Expression);public static string Environ(int Expression);static member Environ : int -> stringPublic Function Environ (Expression As Integer) As StringParameters
- Expression
- Int32
Required. Expression that evaluates either a string containing the name of an environment variable, or an integer corresponding to the numeric order of an environment string in the environment-string table.
Returns
The string associated with an operating-system environment variable.
Exceptions
Expression is missing.
Examples
This example uses the Environ function to supply the entry number and length of the PATH statement from the environment-string table.
Sub tenv()
    Dim envString As String
    Dim found As Boolean = False
    Dim index As Integer = 1
    Dim pathLength As Integer
    Dim message As String
    envString = Environ(index)
    While Not found And (envString <> "")
        If (envString.Substring(0, 5) = "Path=") Then
            found = True
        Else
            index += 1
            envString = Environ(index)
        End If
    End While
    If found Then
        pathLength = Environ("PATH").Length
        message = "PATH entry = " & index & " and length = " & pathLength
    Else
        message = "No PATH environment variable exists."
    End If
    MsgBox(message)
End Sub
Remarks
If Expression contains a string, the Environ function returns the text assigned to the specified environment string - that is, the text following the equal sign (=) in the environment-string table for that environment variable. If the string in Expression cannot be found in the environment-string table, a zero-length string ("") is returned.
If Expression contains an integer, the string occupying that numeric position in the environment-string table is returned. In this case, Environ returns all of the text, including the name of the environment variable. If there is no environment string in the specified position, Environ returns a zero-length string.
Important
The Environ function requires environment permission, which might affect its execution in partial-trust situations. For more information, see SecurityPermission and Code Access Permissions.