X++ Keywords

Article
05/18/2015

Applies To: Microsoft Dynamics AX 2012 R3, Microsoft Dynamics AX 2012 R2, Microsoft Dynamics AX 2012 Feature Pack, Microsoft Dynamics AX 2012

The X++ keywords shown in the following table are reserved. These keywords cannot be used for any other purpose.

Reserved word	Description	More information
!	Not.	Relational Operators
!=	Inequality operator (not equal to).	Relational Operators
#	Prefix on macro names.	How to: Use #define and #if to Test a Macro
&	Binary AND.	Arithmetic Operators
&&	Logical AND.	Relational Operators
(	Function call operator, which indicates the beginning of the function call.
)	Function call operator, which indicates the end of the function call.
*	Multiply. The asterisk (*) is also used in X++ SQL. One use is to signify all fields from the tables on a select statement. Another use is as a wildcard with the like operator, to signify 0 to many characters of any kind. The like operator also uses the ? character.	Arithmetic Operators
^	Binary XOR.	Arithmetic Operators
\|	Binary OR.	Arithmetic Operators
\|\|	Logical OR.	Relational Operators
~	Not.	Arithmetic Operators
+	Plus.	Arithmetic Operators
++	Increment.	Assignment Operators
+=	Additive assignment.	Assignment Operators
,	Comma operator. Expressions separated by commas are evaluated left-to-right.
-	Minus.	Arithmetic Operators
--	Decrement operator.	Assignment Operators
-=	Subtractive assignment.	Assignment Operators
.	Class member access operator, for example, formRun.run accesses the run method of an object of the class type FormRun.
/	Divide.	Arithmetic Operators
\	Escape in strings. Escapes extra quotation marks, and certain letters such as \t for tab.
@	Escape of keywords. For example, str @abstract; would fail to compile without the @ sign. Also affects literal strings, by negating the effect of the \ escape character, and by enabling the string to span more than one line in the source code. The new line is represented by one character of hexadecimal 0x0A, which is commonly called a line feed. No carriage return character of hexadecimal 0x0D is included, as in 0x0D0A.
:	Field declaration or label specifier. The colon (:) character is also used on the switch statement.
::	Used to call static (class) methods: ClassName::methodName.
;	Terminates statements. Used in for loops or as a separator of statements.
<	Less than.	Relational Operators
<<	Left shift.	Arithmetic Operators
<=	Less than or equal.	Arithmetic Operators
=	Assignment operator. The argument to the left of "=" is set to the value of the argument to the right.	Assignment Operators
==	Returns true if both expressions are equal.	Relational Operators
>	Greater than.	Relational Operators
>=	Greater than or equal.	Relational Operators
>>	Right shift.	Arithmetic Operators
?	Ternary operator. The question mark (?) character is also used by the like operator to signify exactly one character of any kind. The like operator also uses the * character.	Ternary Operator (?)
[	Array declarator, open. Must be used with "]".
]	Array declarator, close. Must be used with "[".
{	Indicates the beginning of a number of statements. The last of these statements must be followed by a "}".
}	Indicates the end of a number of statements. A "{" must appear before the first of these statements.
abstract	Class and method modifier. An abstract class cannot be constructed with the new keyword. An abstract method cannot be called. A table can also be modified as abstract by setting its Abstract property to Yes in the AOT, or by using the DictTable class. The Abstract property defaults to No, and it cannot be set unless the table is extended by another table. Each row in an abstract table must have a dependent row in a derived table. This means that each row in an abstract table has a value greater than 0 (zero) in its InstanceRelationType property field. There are no other effects from marking a table as abstract. Informally, programmers often use the term concrete to describe a class that is non-abstract.	Method Modifiers Table Inheritance Overview
anytype	The method can return any data type.	Anytype
as	Needed when you assign a base class variable to a derived class variable. For example, given a Derived class that extends a Base class, the statement myDerived = myBase as Derived; avoids a compiler error by using the as keyword. This keyword also applies when you assign a base table variable to a derived table variable.	Expression Operators: Is and As for Inheritance
asc	An option on the order by or group by clause in a select statement. The sorting is ascending.	Select Statement Syntax
at	Specifies the position of a print window.	Print Statements
avg	Returns the average of the fields from the rows specified by the group by clause in a select statement.	Select Statement Syntax
break	Immediate exit from code block.	Break Statements
breakpoint	Represents a breakpoint that is set for debugging purposes. To set a breakpoint in your code, write: breakpoint;
by	Part of a reserved term, such as group by and order by.
byref	Specifies that the parameter being passed to the called method is being passed by reference (address), instead of by value. Byref is used in X++ when calling a .NET method that takes a parameter by reference (such as with the C# keywords out or ref).	How to: Use the byref Keyword for CLR Interop.
case	Selection within a switch statement.	Switch Statements
catch	Used in exception handling.	Exception Handling with try and catch Keywords
changeCompany	Changes database settings to another company.	Change Company Design Pattern
class	Declares a class.	Classes in X++
client	Method modifier.	Method Modifiers
container	Specifies a variable of type container.	Containers
continue	Forces the next iteration of a loop.	Continue Statements
count	Returns the number of records from the rows specified by the group by clause in a select statement.	Select Statement Syntax
crossCompany	Causes a select statement to return data for all companies that the user is authorized to read from.	Cross-Company X++ Code Basics
date	Specifies a variable of type date.	Dates
default	Default case within switch statements.	Switch Statements
delegate	A class member that is able to store multiple references to methods in other classes, and to call all those methods when prompted to do so. A delegate can store references to various kinds of methods including the following: static methods on X++ classes instance methods on X++ classes methods on .NET Framework classes	Event Terminology and Keywords X++, C# Comparison: Event
delete_from	Allows you to delete multiple records from the database at the same time.	delete_from
desc	An option on the order by or group by clause in a select statement. The sorting is descending.	Select Statement Syntax
display	Method modifier.	Method Modifiers
div	Integer division.	Arithmetic Operators
do	Beginning of a do...while loop.	Do...while Loops
edit	Method modifier.	Method Modifiers
else	Conditional execution (if...else).	if and if ... else Statements
eventHandler	Must be used each time you either add or delete a method reference from a delegate by using the += or -= operator. For example: myDelegate += eventHandler(OtherClass::myStaticMethod);	Event Terminology and Keywords X++, C# Comparison: Event
exists	Used with join clauses in select statements.	Select Statement Syntax
extends	A class or interface declaration clause. If your class does not explicitly extend another class, your class is considered to extend the Object class (as if you had written "extends Object").	Creating a Subclass
false	Boolean literal.	Booleans
final	Class and method modifier.	Method Modifiers
firstFast	Used in select statements to speed up the fetch for the first row.	Select Statement Syntax
firstOnly	Used in select statements to fetch only the first record. The firstOnly keyword does not guarantee that a maximum of one record is retrieved by an X++ SQL select statement. If the AOS can use the EntireTable cache to satisfy the data demands of the select statement, the firstOnly keyword is ignored.	Select Statement Syntax Set-based Caching
firstOnly10	Same as firstOnly, except returns 10 rows instead of one.
firstOnly100	Same as firstOnly, except returns 100 rows instead of one.
firstOnly1000	Same as firstOnly, except returns 1000 rows instead of one.
flush	Clears an entire table cache. Here is the syntax for the flush statement: YourTable ytBuffer; flush ytBuffer;	Set-based Caching
for	For loop iteration.	For Loops
forceLiterals	Used in select statements to reveal actual values that are used in where clauses to the Microsoft SQL Server database at the time of optimization.	Select Statement Syntax
forceNestedLoop	Forces the SQL Server database to use a nested-loop algorithm to process a particular SQL statement containing a join.	Select Statement Syntax
forcePlaceholders	Used in select statements to instruct the kernel not to reveal the actual values used in where clauses to the Microsoft SQL Server database at the time of optimization.	Select Statement Syntax
forceSelectOrder	Forces the SQL Server database to access the tables in a join in the specified order.	Select Statement Syntax
forUpdate	Selects records exclusively for update. The operation to be performed on the records that are fetched is an update. Depending on the underlying database, the records may be locked for other users.	Select Statement Syntax
from	Part of a select statement. The from clause specifies the table in which the columns exists.	Select Statement Syntax
group	Part of the group by clause in a select statement.	Select Statement Syntax
if	Conditional execution.	if and if ... else Statements
implements	Implements an interface.	Interfaces Overview
insert_recordset	Copies data from one or more tables into one resulting destination table on a single server trip.	insert_recordset
int	Specifies a variable of type integer (32-bit).	Integers
int64	Specifies a variable of type integer (64-bit).	Integers
interface	Interface declaration.	Interfaces Overview
is	Asks whether the object referenced by a class variable either inherits from the given class or is of the given class. For example, given a Derived class that extends a Base class, the expression (myDerived is Base) returns true. This keyword applies to class inheritance and table inheritance.	Expression Operators: Is and As for Inheritance
join	Tables are joined on columns common to both tables. You can generate a single result set based on multiple tables through the use of joins.	Select Statement Syntax
like	Tests for matches by pattern, with wildcard symbols * and ?. The string on the right side of the like operator must use four backslash characters to represent one backslash. Examples follow: ("\\" like "\\" ) //Resolves to false. ("\\" like "\\\\") //Resolves to true.	Relational Operators
maxof	Returns the maximum of the fields from the rows specified by the group by clause.	Select Statement Syntax
minof	Returns the minimum of the fields from the rows specified by the group by clause.	Select Statement Syntax
mod	Returns the integer remainder of the left expression1 divided by the right expression2. Informally this is sometimes called the modulo operator. ((12 mod 7) == 5) is true.
new	Operator. Creates an instance of an anonymous class that is assignment-compatible with the named class/interface reference variables, or allocates memory for an array.
next	Fetches the next record in a table.
noFetch	Indicates that no records are to be fetched at present.	Select Statement Syntax
notExists	Used with join clauses in select statements.	Select Statement Syntax
null	Symbolic constant.
optimisticLock	Forces a statement to run with optimistic concurrency control, even if a different value is set on the table.	Select Statement Syntax
order	Part of the order by clause in a select statement.	Select Statement Syntax
outer	outer join.	Select Statement Syntax
pause	Halts the execution of a job. The user is asked to state whether execution should continue.	Select Statements
pessimisticLock	Forces a statement to run with pessimistic concurrency control, even if a different value is set on the table.	Select Statement Syntax
print	Allows you to display output on the screen.	Print Statements
private	Method access modifier.	Method Access Control
protected	Method access modifier.	Method Access Control
public	Method access modifier.	Method Access Control
real	Specifies a variable of type real.	Reals
repeatableRead	Specifies that no other transactions can modify data that has been read by logic inside the current transaction, until after the current transaction completes. An explicit transaction completes at either ttsAbort or at the outermost ttsCommit. For a stand-alone select statement, the transaction duration is the duration of the select command. However, the database sometimes enforces the equivalent of repeatableRead in individual select statements even without this keyword appearing in your X++ code (depending on how the database decides to scan the tables).	For more information, see the documentation for the underlying relational database product.
retry	Used in exception handling.	Exception Handling with try and catch Keywords
return	Exits from a method.	Declaration of Methods
reverse	Records are returned in reverse order.	Select Statement Syntax
select	The select clause designates which columns or views are shown in the result set.	Select Statements
server	Method modifier.	Method Modifiers
setting	Used with the update_recordset command.	update_recordset
static	Static methods may not refer to instance variables (only to static variables); may be invoked by using the class name rather than on an instance of the class ("MyClass.aStaticProcedure").	Method Modifiers
str	Specifies a variable of type string.	Strings
sum	Returns the sum of the fields from the rows specified by the group by clause in a select statement.	Select Statement Syntax
super	Calls the method that was overridden by the current method.	Table Methods
switch	Switch selection statement.	Switch Statements
tableLock	Obsolete; tableLock is no longer available.
this	A reference to the current instance of the class. Used in X++ code inside a method of the class. Used to reference method members of the class, but not field members of the class. public str getFullName() { // Next statement fails to compile without 'this.'. return this.concatenateFirstAndLastNames(); }	Loosely similar to the system variable that is named element. You use element in form control methods to reference the containing form. For more information, see Using Variables with Forms.
throw	Used in exception handling.	Exception Handling with try and catch Keywords
true	Boolean literal.	Booleans
try	Used in exception handling.	Exception Handling with try and catch Keywords
ttsAbort	Discards all changes in the current transaction.	Transaction Integrity
ttsBegin	Marks the beginning of a transaction.	Transaction Integrity
ttsCommit	Marks the end of a transaction.	Transaction Integrity
update_recordset	Allows the manipulation of row sets within one operation.	update_recordset
validTimeState	Filters rows that are retrieved from a valid time state table by an X++ SQL select statement. For example: select validTimeState(myDateEffective) * from xMyTable; ...or... select validTimeState(myDateFrom, myDateTo) * from xMyTable;	Effects of Valid Time State Tables on Read and Write Operations
void	Identifies a method that does not return a value.	Declaration of Methods
where	Part of a select statement. The where clause specifies the conditions to be satisfied; that is, the rows that you want to include in the result.	Select Statement Syntax
while	Iteration statement. Executes a statement or block repeatedly when a test condition is true.	While Loops while select Statements
window	Allows you to alter the size of the output window.	Print Statements

X++ Keywords

See also

Additional resources