Programming Guide - Actian

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How You Can Create a User ClassTo enhance performance by executing a single database operation when hiringmanagers, the PermanentEmployee class has a private BonusTemp attribute,which is null by default. Because this attribute is private, no value can besupplied by invoking this method on a permanent employee object.The following code is the entire Hire method for PermanentEmployee:method Hire() =declareerrstat = integer not null;enddeclarebeginerrstat = CurMethod.SendSuperclass();if errstat = 0 thenCurObject.NextReviewDate =CurObject.HireDate + '3 months';insert into permemp (emp_num,next_review_date,insurance_plan,bonus_rate)values (:CurObject.EmpNum,:CurObject.NextReviewDate,:CurObject.InsurancePlan,:CurObject.BonusTemp);errstat = CurMethod.DBSession.ErrorNumber;if errstat != 0 thenrollback;CurMethod.InfoPopup(messagetext ='Database insert failed with error ' +varchar(CurMethod.DBSession.ErrorNumber),message_type = MT_ERROR);endif;endif;return errstat;endManager VersionThe only difference between a manager and its PermanentEmployee superclassis that managers are given a bonus rate when hired. Therefore, the script forthe Hire method that is redefined for the Manager subclass is the simplest ofall the classes described.The following code is the entire Hire method script for Manager:method Hire() =declareerrstat = integer not null;enddeclarebeginCurObject.BonusTemp = CurObject.BonusRate;errstat = CurMethod.SendSuperclass();return errstat;end134 <strong>Programming</strong> <strong>Guide</strong>
External ClassesThis script first sets a value for the BonusTemp attribute and then invokes itssuperclass's version of the method. The Manager class's superclass,PermanentEmployee, also invokes the Hire method defined by its superclass,Employee. The SendSuperclass method in this script, therefore, has the effectof superseding the Hire method all the way up the hierarchy.The SendSuperclass method is effective even if the immediate superclass doesnot define the method being superseded. For example, assume that thePermanentEmployee class did not define its own version of the Hire method,but its subclass, Manager, needs to supersede the version defined at the top ofthe hierarchy for the Employee class.In this case, invoking the SendSuperclass method in the Hire method forManager automatically invokes the current method as it was defined byEmployee. The Manager class's script does not need to specify that it issuperseding the method defined for Employee.For the complete method scripts of the user classes discussed, see the userclass components in the online Videos application.External ClassesAn external class defines the class properties, methods, and events for one ormore external objects. An external class provides a wrapper for a singleexternal object so that OpenROAD can use it seamlessly in your application.This wrapper provides display and storage space for the external object in yourOpenROAD application. For instance, it allows a spreadsheet, word processor,or other application to be used within an OpenROAD application. OpenROADcan use a Microsoft Excel spreadsheet as an external object, read data from it,and use the data in OpenROAD code.ActiveX SupportExternal classes let you use ActiveX controls and ActiveX automation in yourOpenROAD applications.ActiveX objects have properties, methods, and events just like other classobjects. Therefore, they are treated as external classes in OpenROAD. Eachunique ActiveX object used in OpenROAD must have an external class torepresent it. The external class is viewed by OpenROAD as an actual systemclass. As such, external classes can be displayed and manipulated like anyother class in the system.For more information about ActiveX, see the documentation supplied with theActiveX object.Working with Classes 135
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Ingres OpenROAD ® 2006Programming
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ContentsChapter 1: Introduction 13I
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Using an Object-oriented Approach t
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How You Can Retrieve Array Informat
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Chapter 12: Managing Event Queues 3
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Chapter 17: Preprocessing Your 4GL
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Chapter 1: IntroductionThis section
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ConventionsConventionsThe following
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Your Support OptionsYour Support Op
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OpenROAD NamesThe rules for these n
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OpenROAD Names3. Enclosing field sc
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OpenROAD NamesThe following code ex
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VariablesThe following illustrates
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VariablesIn the first example, film
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VariablesOpenROAD checks references
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VariablesHow You Can Declare Dynami
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VariablesFor example, assume that y
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ExpressionsHowever, you cannot use
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ExpressionsThe general syntax for h
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ExpressionsCurSessionSpecifies, for
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ExpressionsString OperatorThe conca
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ExpressionsOperatorlikenot likeOper
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Expressions• You can use the esca
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ExpressionsBecause procedures can r
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System-defined FunctionsThis rule h
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System-defined FunctionsNameOperand
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System-defined FunctionsName Operan
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System-defined FunctionsNameshift(c
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System-defined FunctionsSome date f
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System-defined FunctionsThe followi
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System-defined FunctionsCount Funct
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System-defined FunctionsResult Data
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Chapter 3: Writing Scripts and Proc
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ScriptsDeclare local variables that
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ScriptsUserEventSpecifies a user ev
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ScriptsExample—Field and Menu Ite
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ProceduresOpenROAD lets you create
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ProceduresReturning from a Procedur
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ProceduresExample—Local Procedure
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Procedures4GL DataTypedatemoneyfloa
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Page 96 and 97: How You Can Invoke FramesHow the Cu
Page 98 and 99: How You Can Invoke FramesHow You Ca
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Page 102 and 103: How You Can Invoke FramesFor exampl
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Page 108 and 109: How You Can Invoke Frames• Prompt
Page 110 and 111: How You Can Invoke FramesThe syntax
Page 112 and 113: How You Can Run Non-interactive App
Page 114 and 115: How You Can Reference ObjectsHow Yo
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Page 122 and 123: InheritanceClass RelationshipsYou c
Page 124 and 125: InheritanceYou can specify a user c
Page 126 and 127: InheritanceThe Terminate method is
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Page 130 and 131: How You Can Create a User ClassHow
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Page 136 and 137: External ClassesHow You Can Use Ext
Page 138 and 139: External ClassesExample—ActiveX C
Page 140 and 141: How You Can Manipulate Objects Gene
Page 142 and 143: Overview of the OpenROAD System Cla
Page 148 and 149: How You Can Access a Database with
Page 182 and 183: How You Can Manage TransactionsHow
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How You Can Manage TransactionsDivi
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How You Can Manage TransactionsTo c
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How Programming for Multiple Sessio
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Handling Database ErrorsIn OpenROAD
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Handling Database ErrorsIf a databa
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Handling Database ErrorsFor example
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Handling Database Errorsbeginerr_no
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Arrays and Table Fields—Conceptua
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ArraysBecause an individual attribu
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ArraysDeclaring an array variable d
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ArraysThe following statement puts
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Arraysfor i = custtable.FirstRow to
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ArraysHow You Can Add Rows to an Ar
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ArraysThe inserted row is blank bec
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ArraysThe following code fragment i
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ArraysThese attributes are:AllRowsR
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ArraysAttributes used in a sort can
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ArraysThe format parameter can be a
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Table FieldsTable Fields and Associ
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Table FieldsThe following applicati
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Table FieldsThis syntax references
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Table FieldsFor example, the follow
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Table Field OperationsTable Field C
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Table Field OperationsHow You Can U
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Table Field OperationsWhen you use
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Table Field OperationsBiases can be
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Table Field OperationsThe following
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Table Field OperationsHow You Can T
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Table Field OperationsTableField Me
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Table Field OperationsFor example,
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Table Field OperationsControlling M
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CollectionsCollectionsA collection
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Collections// Open a workbook and p
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Listview_Treeview_DemoImport the De
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Listview FieldsListview FieldsA lis
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Listview FieldsextensionSpecifies a
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Listview FieldsImageIndexSpecifies
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TreeNode and Tree ClassesHeaderClic
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TreeNode and Tree ClassesMaintenanc
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Treeview FieldsHow You Can Build a
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Treeview FieldsThe second window is
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Treeview FieldsThe tree_ex2_class h
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Chapter 9: Working with Images and
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How You Can Work with ImagesThe fol
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How You Can Work with ImagesThe Col
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How You Can Work with ImagesThe Bit
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How You Can Work with Images5. Add
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How You Can Work with Text StringsD
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How You Can Work with Text StringsH
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How You Can Call 3GL ProceduresIn t
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How You Can Use Exec 4GL Statements
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How You Can Link 3GL ProceduresHow
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Sample 3GL ProceduresExec 4GL and E
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How You Can Use Data Entry Error Ha
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Chapter 12: Managing Event QueuesTh
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Event-based ProgrammingThe followin
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Event-based ProgrammingEvent TypesT
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Event-based ProgrammingField Events
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Event-based ProgrammingBecause all
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Event-based ProgrammingThe followin
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Event-based ProgrammingThe resume s
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Event-based ProgrammingNote: The da
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Communicating Between OpenROAD Fram
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How You Can Communicate with an Ext
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How You Can Communicate Between Ope
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How You Can Communicate Between Ope
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Chapter 14: Creating Dynamic Frames
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How You Can Change Field and Frame
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How You Can Create and Modify Field
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How You Can Remove Fields Dynamical
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How You Can Declare a Composite Fie
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How You Can Manipulate Data in Dyna
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How You Can Manage Operations with
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How You Can Build a Frame Dynamical
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Dynamic Statements ConsiderationsDy
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How You Can Write an AssistantNote:
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How You Can Write an AssistantFirst
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How You Can Write an AssistantBecau
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How You Can Ensure Compatibility Be
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Chapter 17: Preprocessing Your 4GL
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PreprocessorGeneral Preprocessor St
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PreprocessorThe #define StatementTh
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Error ProcessingGuidelines for Usin
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Chapter 18: Debugging Your Applicat
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How You Can Test an ApplicationHow
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How You Can Use Break ConditionsTo
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How You Can Use Break Conditions3.
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How You Can Use Break ConditionsWay
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How You Can Use Break ConditionsSet
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How You Can Use Break Conditions•
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How You Can Use Break ConditionsMet
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How You Can Log Trace InformationDa
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How You Can Monitor a Running Appli
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How You Can Monitor a Running Appli
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How You Can Debug Database QueriesT
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How Debugging an Application WorksS
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How Debugging an Application WorksH
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How Debugging an Application WorksW
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How Debugging an Application WorksH
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How Debugging an Application WorksW
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How Debugging an Application WorksL
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How Debugging an Application WorksA
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Appendix A: SQL Syntax SummaryThis
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SQL Syntax Summarygrant all [privil
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OpenSQL Syntax SummaryOpenSQL Synta
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Operating System CommandsThe follow
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BitmapObject classThe BitmapObject
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external classAn external class def
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local variableLocal variables conta
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StringObject classThe StringObject
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Index'' ' (single quotation marks)c
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Attributesdefined • 28referencing
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using to copy data • 244using wit
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application threads • 444array di
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examining values • 473hexadecimal
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Gmoney • 51numeric list • 53pad
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Namesapplication • 21dynamic •
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ReadOps attributesettings • 243Re
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concat function • 54functions •
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event chains • 323event queue •
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