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Functions and CALL Routines

NOTALPHA Function



Searches a character string for a nonalphabetic character, and returns the first position at which the character is found.
Category: Character
Restriction: I18N Level 2

Syntax
Arguments
Details
Comparisons
Examples
Example 1: Searching a String for Nonalphabetic Characters
Example 2: Identifying Control Characters by Using the NOTALPHA Function
See Also

Syntax

NOTALPHA(string <,start>)


Arguments

string

is the character constant, variable, or expression to search.

start

is an optional numeric constant, variable, or expression with an integer value that specifies the position at which the search should start and the direction in which to search.


Details

The results of the NOTALPHA function depend directly on the translation table that is in effect (see TRANTAB System Option) and indirectly on the ENCODING System Option and the LOCALE System Option in the SAS National Language Support (NLS): Reference Guide.

The NOTALPHA function searches a string for the first occurrence of any character that is not an uppercase or lowercase letter. If such a character is found, NOTALPHA returns the position in the string of that character. If no such character is found, NOTALPHA returns a value of 0.

If you use only one argument, NOTALPHA begins the search at the beginning of the string. If you use two arguments, the absolute value of the second argument, start, specifies the position at which to begin the search. The direction in which to search is determined in the following way:

NOTALPHA returns a value of zero when one of the following is true:


Comparisons

The NOTALPHA function searches a character string for a nonalphabetic character. The ANYALPHA function searches a character string for an alphabetic character.


Examples


Example 1: Searching a String for Nonalphabetic Characters

The following example uses the NOTALPHA function to search a string from left to right for nonalphabetic characters.

data _null_;    
   string='Next = _n_ + 12E3;';  
   j=0;  
   do until(j=0);  
      j=notalpha(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=8 c=_
   j=10 c=_
   j=11 c= 
   j=12 c=+
   j=13 c= 
   j=14 c=1
   j=15 c=2
   j=17 c=3
   j=18 c=;
   That's all


Example 2: Identifying Control Characters by Using the NOTALPHA Function

You can execute the following program to show the control characters that are identified by the NOTALPHA function.

data test; 
do dec=0 to 255;
   byte=byte(dec);
   hex=put(dec,hex2.);
   notalpha=notalpha(byte);
   output;
 end;

 proc print data=test;
 run;


See Also

Function:

ANYALPHA Function

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