function collation (conditional function)

The conditional function helps you test certain variable conditions, each of which returns a Boolean value (True or false) based on the inherent test that is being performed.
The IsArray IsArray function determines whether a particular variable is an array subclass.
Usage: bool = IsArray (varname)
If the specified varname is an array, bool is true; otherwise the function returns FALSE.
The IsDate IsDate function determines whether an expression can be converted to a date.
Usage is: bool = IsDate (expr)
BOOL is true if the specified expr can be recognized as a date or time.

The IsEmpty IsEmpty function determines whether the variable has been initialized.
Usage: bool = IsEmpty (varname)
Where result is the date subclass, the variant,year is between 100 and 9999, month is the number between 1 and 12, and day is the number between 1 and 31. A numeric expression in the correct range can be used as an argument. If the expression is invalid, add it to the next larger number.
The IsNull IsNull function determines whether a variable contains valid data (not NULL).
Usage: bool = IsNull (varname)
BOOL is true if the specified varname is null (that is, contains invalid data). Because using a variable containing null in a conditional expression produces null, the IsNull function is advocated when there is a possibility that the variable is null.
The IsNumeric IsNumeric function determines whether a variable has a numeric subclass or whether an expression can be assigned a numeric value.
Usage is: bool = isnumeric (expr)
BOOL is true when expr can be assigned a percentage.
The IsObject IsObject function determines whether the variable is an object subclass.
Usage: bool = IsObject (varname)
BOOL is true when the specified varname is a valid OLE automatic object.
StrComp Unlike other comparison operators, the StrComp function compares two strings for equality or alphabetic order.
Usage: result = StrComp (Str1,str2[,bin])
Where result is a signed numeric type variable, str1 and str2 are string expressions. The Optional bin parameter specifies whether to perform a binary (indicated by a true value) instead of a letter comparison. If both str1 and str2 are null, result is null. Otherwise, set the value of result based on the following list:
Conditional result Value
STR1 < str2-1
STR1 = str2 0
str1 > Str2 +1