Natural for OpenVMS Version 6.3.12 for OpenVMS
 —  Statements  —

DECIDE ON

DECIDE ON
   {

FIRST
EVERY

} [VALUES] [OF]          
    {

operand1
SUBSTRING (operand3,operand5,operand6)

}          
   { VALUES {

operand2 
SUBSTRING (operand4,operand7,operand8)

}
    [[,{

operand2
SUBSTRING (operand4,operand7,operand8)

}] ...
    [: {

operand2
SUBSTRING (operand4,operand7,operand8)

} ]] statement ...}
  [ANY [VALUES]   statement ]
  [ALL [VALUES]   statement ]
  NONE [VALUES] statement
END-DECIDE

This document covers the following topics:

For an explanation of the symbols used in the syntax diagram, see Syntax Symbols.

Related Statements: DECIDE FOR | IF | IF SELECTION | ON ERROR

Belongs to Function Group: Processing of Logical Conditions


Function

The DECIDE ON statement is used to specify multiple actions to be performed depending on the value (or values) contained in a variable.

Note:
If no action is to be performed under a certain condition, you must specify the statement IGNORE in the corresponding clause of the DECIDE ON statement.

Top of page

Syntax Description

Operand Definition Table:

Operand Possible Structure Possible Formats Referencing Permitted Dynamic Definition
operand1   S A   N A U N P I F B D T L   G O yes no
operand2 C S A     A U N P I F B D T L   G O yes no
operand3   S A     A U         B             yes no
operand4 C S A     A U         B             yes no
operand5 C S           N P I   B *             yes no
operand6 C S           N P I   B *             yes no
operand7 C S           N P I   B *             yes no
operand8 C S           N P I   B *             yes no

* Format B of operand5, operand6, operand7 and operand8 may be used only with a length of less than or equal to 4.

Syntax Element Description:

Syntax Element Description
FIRST/EVERY
Processing of Values:

With one of these keywords, you indicate whether only the first or every value that is found is to be processed.

operand1
Selection Field:

As operand1 or operand2 you specify the name of the field whose content is to be checked.

VALUES operand2 [[,operand2] ... [:operand2]statement ...
VALUES Clause:

With this clause, you specify the value (operand2) of the selection field, as well as the statement(s) which are to be executed if the field contains that value.

You can specify one value, multiple values, or a range of values optionally preceded by one or more values.

Multiple values must be separated from one another either by the input delimiter character (as specified with the session parameter ID) or by a comma. A comma must not be used for this purpose, however, if the comma is defined as decimal character (with the session parameter DC).

For a range of values, you specify the starting value and ending value of the range, separated from each other by a colon.

SUBSTRING (operand3,operand5,operand6)
SUBSTRING Option:

Without the SUBSTRING option, the whole content of a field is checked. The SUBSTRING option allows you to check only a certain part of an alphanumeric, Unicode or binary field.

After the field name (operand3), you specify first the starting position (operand5) and then the length (operand6) of the field portion to be checked.

SUBSTRING (operand4,operand7,operand8)
SUBSTRING Option:

After the field name (operand4), you specify first the starting position (operand7) and then the length (operand8) of the field portion to be checked.

ANY statement
ANY Clause:

With ANY, you specify the statement(s) which are to be executed if any of the values in the VALUES clause are found. These statements are to be executed in addition to the statement specified in the VALUES clause.

ALL statement
ALL Clause:

With ALL, you specify the statement(s) which are to be executed if all of the values in the VALUES clause are found. These statements are to be executed in addition to the statement specified in the VALUES clause.

The ALL clause applies only if the keyword EVERY is specified.

NONE statement
NONE Clause:

With NONE, you specify the statement(s) which are to be executed if none of the specified values are found.

END-DECIDE
End of DECIDE ON Statement:

The Natural reserved word END-DECIDE must be used to end the DECIDE ON statement.

Top of page

Examples

Example 1 - DECIDE ON with FIRST Option

** Example 'DECEX3': DECIDE ON (with FIRST option)                      
************************************************************************
*                                                                       
SET KEY ALL                                                             
INPUT 'Enter any PF key' /                                              
      'and check result' /                                              
*                                                                       
DECIDE ON FIRST VALUE OF *PF-KEY                                        
  VALUE 'PF1'                                                           
    WRITE 'PF1 key entered.'                                            
  VALUE 'PF2'                                                           
    WRITE 'PF2 key entered.'                                            
  ANY VALUE                                                             
    WRITE 'PF1 or PF2 key entered.'                                     
  NONE VALUE                                                            
    WRITE 'Neither PF1 nor PF2 key entered.'                            
END-DECIDE                                                          
*                                                                       
END

Output of Program DECEX3:

 Enter any PF key
 and check result

Output after pressing PF1:

Page      1                                                  05-01-11  15:08:50
                                                                               
PF1 key entered.                                                               
PF1 or PF2 key entered.

Example 2 - DECIDE ON with EVERY Option

** Example 'DECEX4': DECIDE ON (with EVERY option)                      
************************************************************************
DEFINE DATA LOCAL                                                       
1 #FIELD (N1)                                                           
END-DEFINE                                                              
*                                                                       
INPUT 'Enter any value between 1 and 9:' #FIELD (SG=OFF)                
*                                                                       
DECIDE ON EVERY VALUE OF #FIELD                                         
  VALUE 1 : 4                                                           
    WRITE 'Content of #FIELD is 1-4'                                    
  VALUE 2 : 5                                                           
    WRITE 'Content of #FIELD is 2-5'                                    
  ANY VALUE                                                             
    WRITE 'Content of #FIELD is 1-5'                                    
  ALL VALUE                                                             
    WRITE 'Content of #FIELD is 2-4'                                    
  NONE VALUE                                                            
    WRITE 'Content of #FIELD is not 1-5'
    END-DECIDE
*          
END

Output of Program DECEX4:

ENTER ANY VALUE BETWEEN 1 AND 9: 4

After entering and confirming 4:

Page      1                                                  05-01-11  15:11:45
                                                                               
Content of #FIELD is 1-4                                                       
Content of #FIELD is 2-5                                                       
Content of #FIELD is 1-5                                                       
Content of #FIELD is 2-4

Top of page