put does not preserve blanks?

[xxformat_com]

Hi,

The SAS Online Doc suggests that the difference between the put function using a character format and the input function using a character informat would be the way trailing blanks would be managed. See example 4

From earlier experiences, I can remeber using -l to left align the result of character values created using the put function and have trailing blank then.

However when testing some code I cannot reproduce such case.

data test;
    length a $8;
    a='123.15'; output;
    a='12345';  output;
    a='-123';   output;
run;

data _null_;
    set test;
    a1=input(a,$20.);
    a2=put(a,$20.);

    put 'Start' a1 'End';
    put 'Start'  a2 'End';
run;

[Kurt_Bremser]

You use the PUT Statement in List mode. From the documentation (see the link):

Using List Output

With list output, you list the names of the variables whose values you want written, or you specify a character string in quotation marks. The PUT statement writes a variable value, inserts a single blank, and then writes the next value. Missing values for numeric variables are written as a single period. Character values are left-aligned in the field; leading and trailing blanks are removed. To include blanks (in addition to the blank inserted after each value), use formatted or column output instead of list output.

(emphasis by me)

[Kurt_Bremser]

PS your example which you linked to is from the documentation of the SAS Component Language, which is different in many ways from the data step language.

SCL is something you will rarely (most likely never) need. Always start your inquiry into SAS programming documentation here (and make sure Google searches land you within this area):

Programming Documentation for SAS® 9.4 and SAS® Viya® 3.5 

[ballardw]

---

@xxformat_com wrote:

From earlier experiences, I can remeber using -l to left align the result of character values created using the put function and have trailing blank then.

---

That -L in a put is typically used with NUMERIC formats because the default behavior with numeric formats is right justification and put with  something like x=Put(4, f8.) will result in a value for x with 7 leading spaces before the 4. Character formats by default left justify so if you think you need a leading space using Put with a character value then you use the -R to right justify.

Examples with literal values so no one has to guess what the actual values or properties of not documented variables might be:

data junk;
   x=put(4,f8.);
   x2=put(4,f8. -L);
   y=put('A', $10. -r);
   y2=put('A', $10.);
run;

It might help a lot to show what you are actually attempting to create. Writing to the LOG also has slightly different behavior than creating variables because the lines in the LOG can contain many values from a single PUT. Typically you need to provide some additional information such as column position adjustments such as in the following to ensure one "blank" before the value of a1 and 5 spaces before End.

 put 'Start' +1 a1 +5 'End';

You might also want to test some variants like this:

 put 'Start: ' a1 '    End';

[xxformat_com · Accepted solution]

Thank you @ballardw Your feedback helped me creating the example I was looking for.

Here I use the -r you mentionned to move trailing blanks at the front.

This way we can see that trailing blanks are added in the put function but not in the input function.

proc format;
    value   $sex  'M'  = 'Male'
                  'F'  = 'Female';
    invalue $sex  'M'  = 'Male'
                  'F'  = 'Female';
run;

data class;
    set sashelp.class;
    new_put  =put  (sex,$sex.-r);
    new_input=input(sex,$sex.-r);
run;

ods listing file="&xxtraining./class.lst";
proc print data=class (obs=8) noobs;
   var sex new:;
run;
ods listing close;

As a whole, I'm looking for any benefit in using input function (char informat) over put function (char format).

So far, trailing blanks is the only one I could identify.

[Tom]

I am surprised that SAS would even allow those -R modifiers on an INFORMAT.

What would that even mean?

If you don't want INPUT statement or INPUT() function to remove leading spaces when reading a character variable from text use the $CHAR informat. 

With INPUT statement you can also use the $VARYING informat, but I doubt that would work with INPUT() function as there is no way to provide it the extra length information it needs.