Evaluate an expression.
Syntax
Eval (StringExpr)
Key
StringExpr Any expression that returns a string or a number.
The argument stringexpr must be an expression that is stored in a string. If you pass to the Eval function a string that doesn't contain a numeric expression or a function name but only a simple text string, a run-time error occurs. For example, Eval("Smith") results in an error.
Examples
Eval("1 + 1") returns 2.
Eval("1=2") returns False (-1)
Eval("5 * 10") returns 50
strResult = Eval("MY_Function()")
MsgBox strResult 'displays the result of the function
Dim strName As String
strName = "Forms!frmPatients!txtPatientsName"
MsgBox Eval(strName)
' Returns the patients name,
' i.e. the same as Msgbox Me!txtPatientsName
In general, if there is a more direct way of evaluating an expression without using Eval() you should use it.
“More people are killed every year by pigs than by sharks, which shows you how good we are at evaluating risk” ~ Bruce Schneier
Related:
Access Form References - Evaluating references to controls on forms and subforms.
Nz - Detect a NULL value or Zero Length string.