IFN Function

Returns a numeric value based on whether an expression is true, false, or missing.

Category:	Numeric
Restriction:	I18N Level 2 functions are designed for use with SBCS, DBCS, and MBCS (UTF8).

Syntax

IFN(logical-expression, value-returned-when-true, value-returned-when-false
<,value-returned-when-missing> )

Required Arguments

logical-expression

specifies a numeric constant, variable, or expression.

value-returned-when-true

specifies a numeric constant, variable, or expression that is returned when the value of logical-expression is true.

value-returned-when-false

specifies a numeric constant, variable, or expression that is returned when the value of logical-expression is false.

Optional Argument

value-returned-when-missing

specifies a numeric constant, variable or expression that is returned when the value of logical-expression is missing.

Details

The IFN function uses conditional logic that enables you to select among several values based on the value of a logical expression.

IFN evaluates the first argument, then logical-expression. If logical-expression is true (that is, not zero and not missing), then IFN returns the value in the second argument. If logical-expression is a missing value, and you have a fourth argument, then IFN returns the value in the fourth argument. Otherwise, if logical-expression is false, IFN returns the value in the third argument.

The IFN function, an IF/THEN/ELSE construct, or a WHERE statement can produce the same results. (See examples.) However, the IFN function is useful in DATA step expressions when it is not convenient or possible to use an IF/THEN/ELSE construct or a WHERE statement.

Comparisons

The IFN function is similar to the IFC function, except that IFN returns a numeric value whereas IFC returns a character value.

Examples

Example 1: Calculating Commission Using the IFN Function

In the following example, IFN evaluates the expression TotalSales > 10000. If total sales exceeds $10,000, then the sales commission is 5% of the total sales. If total sales is less than $10,000, then the sales commission is 2% of the total sales.

data _null_;
   input TotalSales;
   commission=ifn(TotalSales > 10000, TotalSales*.05, TotalSales*.02);
   put commission=;
   datalines;
25000
10000
500
10300
;
run;

SAS writes the following output to the log:

commission=1250
commission=200
commission=10
commission=515

Example 2: Calculating Commission Using an IF/THEN/ELSE Construct

In the following example, an IF/THEN/ELSE construct evaluates the expression

TotalSales
                     > 10000

. If total sales exceeds $10,000, then the sales commission is 5% of the total sales. If total sales is less than $10,000, then the sales commission is 2% of the total sales.

data _null_;
   input TotalSales;
   if TotalSales > 10000 then commission = .05 * TotalSales;
      else commission = .02 * TotalSales;
   put commission=;
   datalines;
25000
10000
500
10300
;
run;