Tips and Techniques: '00208' Is Possible in Free-Format

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

The MOVE opcode was great for converting numeric data into character. That is, it was great at moving numeric data to a character field. MOVE does something that isn't directly supported by the EVAL opcode; it allows you to move the data and zero-fill the result. EVAL can't do this.


The EVAL opcode does not allow you to copy numeric fields to character fields, nor does it allow you to copy character fields containing numbers into numeric fields. MOVE always supported this capability.

Many people use the %CHAR built-in function to circumvent this shortcoming, as follows:







     D szText          S              5A
     D nItem           S              5P 0 Inz(208
     
     C                   eval      szText = %char(nItem)

The code above results in szText containing '208 ' (the number 208 left-justified in the szText field and followed by two blank characters).

Since V5R2, you can copy the value in szText to nItem using the %DEC or %INT built-in functions, as follows:

     D szText          S              5A   Inz('208')
     D nItem           S              5P 0  
     
     C                   eval      nItem = %Dec(szText)

But how do you replace the MOVE feature that would produce '00208' when copying nItem to szText?

The answer is %EDITC(). This built-in function applies the indicated edit code to the numeric value and then copies the result as text to the target field. Here's an example:

     D szText          S              5A
     D nItem           S              5P 0 Inz(208
     
     C                   eval      szText = %EditC(nItem:'X')

The above example results in szText containing '00208'.

(Note: The 'X' edit code is an RPG-specific edit code and is not available if you're using DDS or other editing tools, such as the "Edit" APIs.)

If you want to ensure that the result is right-justified and zero-filled, use the EVALR opcode, as follows:

     D szText          S              5A
     D nItem           S              5P 0 Inz(208
     
     C                   evalR     szText = %EditC(nItem:'X')

The EVALR opcode was introduced in V4R2, so it is virtually available on all iSeries systems today.

What about negative numbers? What happens in the following example code?

     D szText4         S              4A
     D szText5         S              5A
     D szText6         S              6A
     D szText7         S              7A
     D nItem           S              5P 0 Inz(-208)
                                                                 
     C                   eval      szText4 = %EditC(nItem:'X')
     C                   eval      szText5 = %EditC(nItem:'X')
     C                   eval      szText6 = %EditC(nItem:'X')
     C                   eval      szText7 = %EditC(nItem:'X')

The results from the above example would set the fields szText4 to szText7 to the following values:

Field
Value
szText4
0020
szText5
0020Q
szText6
0020Q_
szText7
0020Q__

Note that in szText4, the minus sign and the low-order digit are truncated, but in all other fields, the letter "Q" is used as the minus sign. This is a shortcoming in the 'X' edit code; there really isn't a way to have it embed a minus sign. But you can do it manually, as follows:

     D szText          S             10A
     D nItem           S              5P 0 Inz(-208)
     D szSign          S              1A   Inz Varying
                                                
     C                   if        nItem < 0
     C                   eval      nItem = %abs(nItem)
     C                   eval      szMinus = '-'
     C                   endif
                                             
     C                   eval      szText = szSign + %EditC(nItem:'X')

This example causes szText to contain '-00208' left-justified.

The last problem is when the numeric value contains decimal digits. The 'X' edit code ignores decimal positions, so you again have to do it yourself. Here's one technique that I came up with:

     D szText          S             10A
     D nSales          S              7P 2 Inz(-208.50)
     D szMinus         S              1A   Inz Varying
                                  
     C                   if        nSales< 0
     C                   eval      nSales= %abs(nSales)
     C                   eval      szMinus = '-'
     C                   endif
                                    
     C                   eval      szText = szMinus + 
     C                                     %EditC(nSales:'X')
     C                   eval      szText = %subst(szText:1:
     C                               %Len(%trimR(szText)) -  
     C                                    %DecPos(nSales))
     C                                  + '.' +
     C                                %subst(szText:
     C                                  %Len(%trimR(szText)) - 
     C                                    %DecPos(nSales)+1)

This may not be elegant, but it works. The result is '-00208.50' left-justified in the szText field. The technique incorporates the %DECPOS built-in function that extracts the number of decimal positions for the corresponding field.

You can move numeric to character fields and get the data in just about any format you want. You just have to work at it a little.

Bob Cozzi is a programmer/consultant, writer/author, and software developer of the RPG xTools, a popular add-on subprocedure library for RPG IV. His book The Modern RPG Language has been the most widely used RPG programming book for nearly two decades. He, along with others, speaks at and runs the highly-popular RPG World conference for RPG programmers.

BOB COZZI

Bob Cozzi is a programmer/consultant, writer/author, and software developer. His popular RPG xTools add-on subprocedure library for RPG IV is fast becoming a standard with RPG developers. His book The Modern RPG Language has been the most widely used RPG programming book for more than a decade. He, along with others, speaks at and produces the highly popular RPG World conference for RPG programmers.


MC Press books written by Robert Cozzi available now on the MC Press Bookstore.

RPG TnT RPG TnT
Get this jam-packed resource of quick, easy-to-implement RPG tips!
List Price $65.00

Now On Sale

The Modern RPG IV Language The Modern RPG IV Language
Cozzi on everything RPG! What more could you want?
List Price $99.95

Now On Sale

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  •  

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: