Booleans [AX 2012]
Updated: September 21, 2011
Applies To: Microsoft Dynamics AX 2012 R3, Microsoft Dynamics AX 2012 R2, Microsoft Dynamics AX 2012 Feature Pack, Microsoft Dynamics AX 2012
The boolean data type contains a value that evaluates to either true or false. You can use the X++ reserved literals true and false where ever a Boolean expression is expected.
Boolean expressions are also named logical expressions.
In X++ the internal representation of a boolean is an integer. You can assign any integer value to a variable declared of type boolean. The integer value 0 (zero) evaluates to false, and all others evaluate to true.
The X++ literal false is the integer value 0, and true is 1.
The following table lists several expressions and indicates whether they evaluate to true or false.
|
Expression |
Boolean value |
|---|---|
|
1 |
True |
|
44 |
True |
|
true |
True |
|
(false == 0) |
True |
|
(true == 1) |
True |
|
(true == 8) |
False |
|
false |
False |
|
0 |
False |
|
Boolean declaration |
= |
boolean variable { , variable } ; |
|
variable |
= |
identifier [ option ] |
|
option |
= |
Arrayoptions | initialization |
// Simple declaration of a boolean variable, b boolean b; // Multiple declaration boolean b1,b2; // Boolean variable is initialized to true boolean b3 = true; // Declares a dynamic array of Booleans boolean b4[];
You usually use Booleans in conditional statements, or as parts or results of logical expressions. The following example shows both.
void main()
{
//Declares a boolean called exprValue
boolean exprValue;
//Assigns ExprValue the truth value of (7*6 == 42)
exprValue = (7*6 == 42);
;
if (exprValue)
{
print "OK";
}
}
Here, the variable exprValue contains the value true, because 7*6 is equal to 42; so, the expression is true. The conditional statement is true; the word "OK" is displayed on the screen.
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