Eval Function
Evaluates an expression and returns the result.
Syntax
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