SAS/Macro String Replace Function

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Contents 1 Description 2 Code 3 Usage 4 By 5 Alternative Approach

[edit] Description

I can hardly believe there is not something like this already in SAS/Base. I asked around me, search the web, browsed the docs. unfortunately without success. These are not super solid functions, they might failed in various circumstances. but it worked for me and answer the need I had. I first needed something that would replace the first occurrence in a SAS/Macro variable. Then I modified it to loop until all occurrences are replaced. I hope this help for you, use at your own risk.

[edit] Code

%macro singlereplace(in_what, from_what, to_what);                              
    %let pos_fw = %index(&in_what, &from_what);                                 
    %if &pos_fw > 0 %then %do;                                                  
        %let l_str = %substr(&in_what, 1, %eval(&pos_fw - 1));                  
        %let r_str = %substr(&in_what, %eval(&pos_fw + %length(&from_what)));   
        &l_str&to_what&r_str                                                    
    %end; %else %do;                                                            
       &in_what                                                                 
    %end;                                                                       
%mend;                                                                          
                                                                                
%macro strreplace(in_what, from_what, to_what);                                 
    %let s=&in_what;                                                            
    %do %while(%index(&s, &from_what) > 0);                                     
        %let pos_fw = %index(&s, &from_what);                                   
        %if &pos_fw > 0 %then %do;                                              
            %let l_str = %substr(&s, 1, %eval(&pos_fw - 1));                    
            %let r_str = %substr(&s, %eval(&pos_fw + %length(&from_what)));     
            %let s=&l_str&to_what&r_str;                                        
        %end;                                                                   
    %end;                                                                       
    &s                                                                          
%mend;         

[edit] Usage

%let str1=I_WISH_THERE_WOULD_BE_NO_UNDERSCORE_IN_THIS_STRING;
%let ts=%strreplace(&string, _, );

[edit] By

User:Mathieu

[edit] Alternative Approach

Instead of creating a new macro that needs to be stored and maintained one could perform the operation with a single line of macro code.

%Let StringToModify = This_Is_The_String_To_Modify ;
%Let ModifiedString = %SysFunc( TranWrd( &StringToModify , _ , %Str( ) ) ) ;
%Put ModifiedString = &ModifiedString ;

Copyright (C) 2008 Paul OldenKamp
The above code is free software; you can redistribute it and/or modify it under the 
terms of the GNU General Public License as published by the Free Software Foundation; 
version 3 of the license.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
See the GNU General Public License for more details.

The GNU General Publice License can be obtained at http://www.gnu.org/licenses/gpl.html

Copyright (c) 2008 Paul OldenKamp
Permission is granted to copy, distribute and/or modify (the non-code portions of) this
document under the terms of the GNU Free documentation License, Version 1.1 or any later
version published by the Free Software Foundation; with no Invariant Sections; and with
no Front-Cover Texts; and with no Back-Cover Texts.

A copy of this license can be obtained at http://www.gnu.org/licenses/fdl.html

--Paul OldenKamp