Spacing between Concatenated Strings

Dear Readers:

A neat feature of RPG's CAT op code that I have used from time to time is its ability to insert a specified number of blanks between two concatenated values. The number of blanks is specified in Factor 2, following a string and a colon (:). The new way to concatenate in RPG is by using the plus sign (+) operator, but the plus sign doesn't support the specified number of blanks option. One reader has developed a solution, and today I pass it along to you.

-- Ted

Hey, Ted:

Sometimes when I'm concatenating strings together using the various %TRIM functions, I want to put one or more spaces between two values in the same field, which is a simple task:

That nice little space, enclosed in single quotes ('), is the point I illustrate. There are times when I want to use one line of code to do a concatenation where I might have one space one time and then two, three, or even more spaces the next time. Sometimes I don't want spaces.

I could code four or five different lines that are all the same, except for the number of spaces between the single quotes, but I prefer to have one line of code where I replace the single-quoted space constants with a variable length field. I can set the length of the spacer field to be equal to the number of spaces I want between the two values each time I run it. And here's the coolest feature: If I set the length of the field to zero, then no spaces are inserted.

In the following code, I run an EVAL statement three times, changing the length of the variable-length field SPACER, each time.

D C1              c                   'ABC'
D C2              C                   'DEF'
D Spacer          s             10    varying
D X               s              1  0 
D Test            s             20 
   
C     0             DO        2             X 
C                   EVAL      %Len(Spacer) = X
C                   EVAL      Test = C1 + Spacer + C2     
C                   DSPLY                   Test 
C                   ENDDO 

The %LEN function sets the length of the SPACER field to zero, one or two bytes long respectively during the three tours through the loop. The results of running this program are below:

DSPLY  ABCDEF
*N
DSPLY  ABC DEF
*N
DSPLY  ABC  DEF

-- John Chadwick, Project Leader
DMC Consulting, Inc.
johnl.chadwick@dmcconsulting.com

Thanks for sharing this idea with us, John. This technique would be even more useful when inserting large numbers of blanks between two character strings.

The only other idea I have along these lines comes from Visual Basic (VB), a language with which I spend a lot of time these days. VB has a SPACE function, which returns a string of a specified number of spaces. The following VB code inserts 57 spaces between two string values.

Dim c1 As String
Dim c2 As String
Dim test As String

c1 = "ABC"
c2 = "DEF"

test = c1 & Space(57) & c2

An equivalent RPG function can be written. In the following example, SPACER is a function that returns up to 4096 blanks. The number of blanks to be inserted may be passed as a literal or variable.

H dftactgrp(*no)
  
D Spacer          pr          4096    varying 
D  NbrOfBlanks                  10u 0 value
  
D C1              c                   'ABC'
D C2              C                   'DEF'
D X               s              3  0 
D Test            s            128 
   
C                   EVAL      X = 28
C                   EVAL      Test = C1 + Spacer(X) + C2 
    
C                   EVAL      Test = C1 + Spacer(98) + C2
      
C                   EVAL      *INLR = *on
    
P Spacer          b
D Spacer          pi          4096    varying
D  NbrOfBlanks                  10u 0 value
D BlankVar        s           4096    varying
C                   EVAL      %Len(BlankVar) = NbrOfBlanks
C                   RETURN    BlankVar
P                 e

But I think I like your solution better.

-- Ted

Sponsored By inFORM DECISIONS

ELIMINATE THE COSTS OF PRE-PRINTED FORMS, LABOR AND POSTAGE WITH inFORM Decisions iDocs™ 'Suite' iSeries based e-Forms, e-Checks, e-Mail, e-FAX, and Document Retrieval from the Web are available as individual modules or as a complete e-Document processing 'Suite'. Click to Download the Complete Suite or Individual Modules today www.inFORMDecisions.com or call (800) 858-5544