Both IF and IIF functions are logical functions. And like all other logical functions, they allow developers to test whether a certain condition is TRUE or FALSE (boolean logic).
For example, testing whether Sales for different sales agents are below or above target.
While these two functions offer the same solution, there exist a small difference in way of application. Therefore, this article will explore how the two functions differ.
IF Function
IF function tests an expression, returning one variable if the expression is TRUE and another variable if the expression is FALSE or OTHERWISE.
E.g.
IF(x>0,a,b), the interpretation to this expression is. If x is greater than 0, then return ‘a’ else if x is not greater than zero or x is equal to a null (x<=0 or x=null) then return ‘b’.
Written: If x>0 then ‘a’ else ‘b’ END
IIF Function
IIF function on the other hand tests an expression, returning one variable if the expression is TRUE and another variable if the expression is FALSE and another variable if the expression is neither TRUE nor FALSE.
Note: This expression returns Null if the third expression is not specified.
Example
IIF(x>0,a,b), the interpretation to this expression is, if x is greater than 0 (x>0) then return ‘a’, else if x is less or equal to zero (X<=0) then return ‘b’, else if x is neither greater than zero (x>0) nor less or equal to zero (x<=0) then ‘Null’.
Written: IIF(x>0,’a’,’b’)
A more complete (IIF) function would be written
IIF(x>0,a,b,c), interpreted as follows; if x is greater than 0 (x>0) then return ‘a’, else if x is less or equal to zero (x<=0) then ‘b’, else if x is neither greater than zero (x>0) nor less or equal to zero (x<=0) then return ‘c’.
Written: IIF(x>0,’a’,’b’,’c’)
Summary of the functions
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