1) What is the difference betwen abap and sap memories?

Data sending between internal sessions is called abap memory using import and export parameters.
Data sending between main sessions using spa/gpa ie (set /get) parameters called sap memory.

2) What is nast?
nast is a message status database table.

3) How to upload logo in sapscripts?
 1... create a logo using paint shop and save it as tifffile then using RSTXLDMC (is a program name) used to upload logo
 2.....create a logo using paint shop and save it as bmpfile then using SE78 you can do this.

4) What are symbols explain?
Symbols are constants used to save un nessessary  work used in documentation
 1. system symbols : example: &date& &time& etc
 2. text symbols: they are defined using control statements
     protect...endprotect, if endif, etc
 3. standard symbols : all the messages are stored in TTDTG table
 4. program symbols  : used in abap program example: &i_mara-matnr& &i_mara-ernam&

5) Difference b/w  call transaction and session.
           Call transaction                   Ssession
      1.  synchronous updation         only synchronous updation
           optional
      2.  errors can handled              error log is created
           explicitely
      3.  faster                                  slower 
      4.  less amount of data             more can transfer 
      5.  updation takes place           updation takes place
           during program execution   once the session being created

6. Difference b/w smartforms and scripts.
      Script                                   Smartforms
      client dependant                    independant
      not possible                           multiple page formats are possible
      compulsory                           without  main window it can
      labels are used                      labels cannot
      not generated                        once session created function module 
 
7.  Errors hanling in call transaction
 Two ways
 1)... int table decalred having structure BDCMSGCOLL it is having certain variables not texts. ie msgtyp,megid, msgnr, 
msgvar1, msgvar2, msgvar3, msgvar4 etc all the text messages are stored using T100 database table.
 2)....int table decalred having structure BDCMSGCOLL it is having certain variables . ie msgtyp,megid, msgnr, 
msgvar1, msgvar2, msgvar3, msgvar4 etc by declaring function modules format_message or write_message you can handle.

8. Errors handling in session 
 In SM35 error log is created, there you can handle.

9. Difference b/w select-options, valueranges, parameters. 
 par-----  singlevalue
 select-options----range and itself implicitly creates internal table
 value-ranges---- just for ranges 

10. How to remove duplicate entries?
 using COLLECT
 or
 DELECT DUPLICATE ENTRIES FROM TABLENAME>

11. What are standard texts?
 These are predefined texts used for create change and display tcode SO10
 Starting with INCLUDE 
 These are for TERMS AND CONDITIONS .

12. What is the use of select....for all entries?
 Avoid nested select or inner joins
 uses
   fast processing
   sorting
   delete duplicate entries

13. What is the difference b/w exit and continue?
 exit----if it is in the loop comes out of the loop.
      ----if it is in the subroutine comes out of the routine.
      ----if it is in the program comes out of the preogram.
 continue-----unconditional jumping out of the loop.

14. What is the diffenrence b/w collect and append.
 collect----- checks whether it is there or not. if there adds integer,  packed, float otherwise remove
 append-----just adding

15) What are barcodes?
 For security purpose

Tips by : Ramana

What is meant by "Matchcode"?

Matchcodes are defined in two stages in Abap/4 Dictionary:

1) The revelant table and fields are stipulated in matchcode object. A matchcode object describes the set of all possible search paths for a search item.
2) One or more matchcode ID can be defined for a matchcode object.  A matchcode ID describes a special search path for a search term.The fields or combination of fields via which the search is to take place is defined in the matchcode ID.

Tips by : Shankar Varma ( varma_shankar@rediffmail.com )

Fast Links:
Get help for your ABAP problems
Do you have a ABAP Question?

ABAP Books
ABAP Certification, BAPI, Java, Web Programming, Smart Forms, Sapscripts Reference Books

ABAP Tips
ABAP Forum for Discussion and Samples Program Codes for Abapers

Best regards,
SAP Basis, ABAP Programming and Other IMG Stuff
http://www.sap-img.com