If/Then

[swayto]

Practice Question

data word.new;

length word $7;

amount=4;

If amount=4 then word ='four';

else if amount=7 then word = 'seven';

else word='NONE!!!!';

amount=7;

run;

Answer 

Amount Word 

  7 FOUR

Can somebody please explain the rational behind the answer.

[Jagadishkatam]

There is a concept of PDV in SAS, the Program Data Vector is a logical area of memory that is created during the data step processing. SAS builds a SAS dataset by reading one observation at a time into the PDV and, unless given code to do otherwise, writes the observation to a target dataset.So here in the beginning as per the data step, the amount=4; then the same values is used to fill the value of variable amount=4, then the if/then step is read and since amount=4 when its read the word variable is set to FOUR, then again the amount variable is read again and this time since the value is 7 the amount of 4 is overwritten with 7. And since after this there is no if/then the same values will remain and are output.  

[Astounding]

The simple answer: SAS executes statements in the DATA step in order.

First it sets AMOUNT to 4.

Next it calculates WORD.

Next it sets AMOUNT to 7.

Last, it outputs the result.

[Reeza]

The code as shown has an error in the IF condition and likely would error out.

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@swayto wrote:

Practice Question

data word.new;

length word $7;

amount=4;

If amount=4 then word ='four';

else amount=7 then word = 'seven';

else word='NONE!!!!';

amount=7;

run;

Answer 

Amount Word 

  7 FOUR

Can somebody please explain the rational behind the answer.

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[swayto]

Sorry else if