MsgBox VarType var1. MsgBox IsEmpty var1. MsgBox IsNull var1. MsgBox "Empty Variable represented as Zero". End If. End Sub. Example - Testing for Empty:. Sub EmptyCheck 'testing for Empty. Dim var1 As Variant. Example - Initialize a Variant variable:.
Sub VarInitialized 'initialized variable. MsgBox "Variable value is Zero". Example - Check a zero-length string:. Sub CheckZLS 'check a zero-length string. MsgBox "True". In VBA, Null keyword is used to indicate that a variable contains no valid data. A value indicating that a variable contains no valid data. Null is the result - i if you explicitly assign Null to a variable, or ii if you perform any operation between expressions that contain Null. The Null keyword is used as a Variant subtype ie.
Null is not the same as a zero-length string "" , and neither is Null the same as Empty, which indicates that a variable has not yet been initialized. If you try to get the value of a Null variable or an expression that is Null, you will get an error of 'Invalid use of Null' Run-time Error You will need to ensure the variable contains a valid value. Refer Image 1. IsNull Function. The IsNull Function returns a Boolean value - True for an expression that is Null containing no valid data , or else False for an expression that contains valid data.
Syntax: IsNull expression. The expression argument is a variant that contains a numeric or string value, and is necessary to specify. Example - Integer variable:. Sub VarInteger 'no beginning value assigned to a variable of subtype Integer.
Dim intVar As Integer. MsgBox IsNull intVar. MsgBox VarType intVar. MsgBox IsNull "Hello". Example - Check a Null variable:. Sub CheckNull 'check a Null variable. MsgBox "Null variable". Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services. Privacy policy. Returns a Boolean value indicating whether a variable has been initialized.
The required expression argument is a Variant containing a numeric or string expression. However, because IsEmpty is used to determine if individual variables are initialized, the expression argument is most often a single variable name.
IsEmpty returns True if the variable is uninitialized, or is explicitly set to Empty ; otherwise, it returns False. In this VBA Tutorial, you learn how to check if a cell or range is empty.
Use the following Table of Contents to navigate to the section you're interested in. Table of Contents. Most Voted Newest Oldest. Inline Feedbacks. Load More Comments.
0コメント