AS-400 Interview Questions and Answers: Part I

What is the maximum number of records you can specify in a display file?
Ans:1024

How can a screen field that has changed since the last output operation be detected ?
Ans:Attach the MDT (modified data tag) attribute to the field, to detect whether field has been changed as a result of user input.

What would be the effect on the field where reverse image, underline and highlight display attributes were active?
Ans:The result is same as if you had specified ND.

What is the use of DSPATR(MDT) keyword?
Ans:Sets on the modified Data Tag of the field. The Data Tag detect whether the field has been changed as a result of user input.

If DSPATR(PC) and CSRLOC were specified for a format, which keyword would have priority?
Ans:CSRLOC gains priority.


Can error messages as a result of a COMP, RANGE or VALUES keyword be overridden?
Ans:Yes, through CHKMSGID keyword.

What the purpose of OVRDTA, OVRATA keywords?
Ans:OVRDTA keyword (field or record level) can be used to override the existing data contents of a field or record already on the display.
OVRATA keyword (field or record level) can be used to override the existing display attributes of a field or record already on the display.

How can a message from a message file appear as a constant on the screen?
Ans:By using MSGCON (message constant) keyword.

In conjunction with what other keyword must OVRDTA and OVRATA be used?
Ans:PUTOVR keyword must used.

What is the purpose of the INDARA keyword?
Ans:This File-level keyword is used to remove option and response indicators from the buffer and places them in 99-byte separate indicator area.

Explain the purpose of KEEP and ASSUME keywords?
Ans:KEEP: Keep the display from being deleted when the display file is closed.
ASSUME: It is used to specify that the OS/400 program is to assume that this record is already shown on the display
when this file is opened.

Explain the use of DFTWRT display keyword?
Ans:No records will be displayed until there is any I/O operation.

What is the purpose of FRCDTA keyword ?
Ans:Immediately display a record format without waiting for the next I/O operation.

What keyword must be used with PROTECT keyword?
Ans:OVERLAY

What is Subfile?
Ans:Subfile is group of records of same record format and can be read from or write to the display in a single operation.

What are all the contents of subfile?
Ans:Subfile Record Format, Subfile Control Record Format, Relative Record Number, Subfile Record Number, Associated Subfile Keywords.

What are the two record formats a subfile contain ?
Ans:Subfile record forma (SFL), and subfile control record forma (SFLCTL).

What is SFLPAG and SFLSIZ ?
Ans:
SFLPAG : it is an attribute which specifies the number of records that can be displayed in a screen.
SFLSIZ : it is an attribute which specifies the number of records can be stored in subfile.

What is the maximum number of subfiles that can be specified in a display file,
Ans:512

Maximum number of subfiles that can Defined in a RPG program for one display file is
Ans:24

Maximum number of subfiles that can be active for a single file is?
Ans:12

Can more than one subfile record be displayed on one line?
Ans:Yes, by using SFLLIN keyword.

How do you specify the number of records to roll in a subfile?
Ans:Use SFLROLVAL keyword in DDS along with number, which specifies the number of records to scroll at a time.

How will you display a particular page in subfile?
Ans:Move a valid relative record number (RRN) in the field specified using SFLRCDNBR keyword in DDS.

How to pick up the changed records every time in a subfile after the first change made?
Ans:Seton SFLNXTCHG keyword indicator and update the subfile record.

What is the use of SFLEND keyword?
Ans:By specifying this keyword, the Bottom/More message could be displayed at end of screen.

How to toggle between single line and Multi - line display of a particular record in a subfile?
Ans:Using SFLDROP keyword.

Explain the difference between defining Subfile and Message-subfile?
Ans:Subfile record is defined by SFL keyword, where as Message subfile is defined by SFLMSG keyword.

What are the different types of variables available in CL?
Ans:DEC, CHAR, LGL

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