The weird but useful NOTNAME() function in SAS

[Justin]

NOTNAME Function
This function searches a character string for an invalid character in a SAS variable name
under VALIDVARNAME=V7, and returns the first position at which that character is found.

Comparisons
The NOTNAME function searches a string for the first occurrence of any character that is not valid in a SAS variable name under VALIDVARNAME=V7. The ANYNAME function searches a string for the first occurrence of any character that is valid in a SAS variable name under VALIDVARNAME=V7.

Examples
The following example uses the NOTNAME function to search a string for any character that is not valid in a SAS variable name under VALIDVARNAME=V7.

 data _null_;    
    string='Next = _n_ + 12E3;';  
    j=0;  
    do until(j=0);  
    j=notname(string,j+1);  
    if j=0 then put +3 "That's all";  
    else do;          
    c=substr(string,j,1);  
    put +3 j= c=;      
    end; 
    end;
run;

The following lines are written to the SAS log:
j=5 c=
j=6 c==
j=7 c=
j=11 c=
j=12 c=+
j=13 c=
j=18 c=;
That’s all

 data _null_;    
    string='Next = _n_ + 12E3;';  
    j=0;  
    do until(j=0);  
       j=anyname(string,j+1);  
       if j=0 then put +3 "That's all"; 
       else do;          
          c=substr(string,j,1);  
          put +3 j= c=;  
       end; 
    end;
 run;

The following lines are written to the SAS log:
j=1 c=N
j=2 c=e
j=3 c=x
j=4 c=t
j=8 c=_
j=9 c=n
j=10 c=_
j=14 c=1
j=15 c=2
j=16 c=E
j=17 c=3
That’s all

Isn’t it cool? Try it in SAS!