Sun Identity Manager Deployment Reference

Data Types

All functions return a value that has one of the data types listed in the following table.

Table 5–1 Return Value Data Types

Data Type 



Represents a signed integral value. The precision of the value is at least 32 bits. 


Represents ordered lists of other values. The values in a list are called elements. List elements can be null. A list lacking elements is not considered to have a null value.


Represents the absence of a value. A function might return null if it is called only for side effect, or if it cannot compute a meaningful value from the given arguments. The way a null value is handled depends on the function being passed a null argument. In general, a null value is considered to be logically false and is ignored in arithmetic expressions. 


Represents references to arbitrary objects that are defined outside the XPRESS language. 


Represents a string of characters. Since XML syntax is used, strings always use the Unicode character set. A string value can contain no characters. Such a string is considered empty, but it is not null.

Some functions treat the values of their arguments as being logically true or false. XPRESS does not use a Boolean data type. Instead, a value of null or an integer value of zero is considered false. Any other value is considered true.

Logical functions such as eq that return a Boolean value will return the integer zero to represent false and the integer 1 to represent true.