A Function That Takes an Optional Argument

A Custom function That takes AN Optional Argument 

A custom function can have optional arguments. Use the Optional keyword in the list of arguments to declare an optional argument. The optional argument or arguments must be last in the list. 

You will need to determine the presence or absence of optional arguments in a procedure by using the IsMissing keyword. As well, you may need to provide a default value if an argument is omitted. 

The MolWt function can be found on the CD-ROM that acompanies this book. 

Function MolWt(formula As String, Optionai decimals) 

A CUSTOM FUNCTION THAT TAKES an Optional Argument 

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