IIf Syntax ( how to read and understand)

[yantan2006]

Good day to all,

I am novice to formulas, functions. i couldn't figure out how to read and understand syntaxes.

I understand "is null" find's blank entry and IIf works similar to "if" function...

Customer Name: IIf(IsNull([Last Name]),IIf(IsNull([First Name]),[Company],[First Name]),IIf(IsNull([First Name]),[Last Name],[First Name] & " " & [Last Name]))


1. could you please help me what does this formula syntax tells?

2. actually please tell me how to read and understand a lengthy syntax?

any web link, book, tutorial you recommend on understanding syntaxes will be appreciated.

Thanks in advance

 

[smozgur]

IIf function consists of 3 parts separated with comma as below:

IIf(comparison_here, this_returns_if_comparison_true, this_returns_if_comparison_false);

Sample: returns true since 1 = 1
IIf(1=1, "true", "false")

More practical sample:returns message according to Role field value
IIf([Role]="Admin", "Welcome Admin", "Welcome User")

Your sample: consist of insider IIfs. You should see all parts separately, so it makes more sense.

IIf(    
    IsNull([Last Name]),
    IIf(
        IsNull([First Name]), 
        [Company], 
        [First Name]
        ),
    IIf(
        IsNull([First Name]), 
        [Last Name], 
        [First Name] & " " & [Last Name]
    )
)

Outer IIf looks if LastName is null or not and executes inner IIfs.

It Looks for LastName is null or not null
    If LastName is null then it looks if FirstName is null or not. 
        If FirstName is null then it returns Company
        Else it returns FirstName
    If LastName is not null then it looks if FirstName is null or not
        If FirstName is null then it returns LastName
        Else it returns concatenation of FirstName and LastName

Very well explained here as well.

Hope it helps.

 

[yantan2006]

I hearty thank you and appreciate your efforts for explaining by breaking it in parts.

May God bless you......

Thank you very much

 

[smozgur]

I hearty thank you and appreciate your efforts for explaining by breaking it in parts.

May God bless you......

Thank you very much

You're welcome

I learned this way, so I thought it might help you as well. Glad to hear it helps.