data _null_;

/* if 4 is a numeric value;*/
num1=4;

* numeric result;
format num1 8.1;

* character result;
num2=put(num1,8.1-l);

/* if "4" is a character value;*/

num3="4";

* numeric result;
num4=input(num3,best.);
format num4 8.1;

* character result;
num5=strip(num3)||".0";

* all results;
put num1=/num2=/num4=/num5=;

run;

thank you!!