Eval Function
Evaluates an expression and returns the result.
Eval(expression)
Arguments
- expression
Required. String containing any legal VBScript expression.
Remarks
In VBScript, x = y can be interpreted two ways. The first is as an assignment statement, where the value of y is assigned to x. The second interpretation is as an expression that tests if x and y have the same value. If they do, the result is True; if they are not, the result is False. The Eval method always uses the second interpretation, whereas the Execute statement always uses the first.
Note
In Microsoft® JScript™, no confusion exists between assignment and comparison, because the assignment operator (=) is different from the comparison operator (==).
The following example illustrates the use of the Eval function:
Sub GuessANumber
Dim Guess, RndNum
RndNum = Int((100) * Rnd(1) + 1)
Guess = CInt(InputBox("Enter your guess:",,0))
Do
If Eval("Guess = RndNum") Then
MsgBox "Congratulations! You guessed it!"
Exit Sub
Else
Guess = CInt(InputBox("Sorry! Try again.",,0))
End If
Loop Until Guess = 0
End Sub