The system function JavaLib.isNull returns a value (1 for true, 0 for false) to indicate whether a specified identifier refers to a null object. JavaLib.isNull is one of several Java™ access functions.
JavaLib.isNull(identifier javaObjId in) returns (result INT)
An identifier that refers to an object in the object space.
This argument is either a string literal or an item of type CHAR, DBCHAR, MBCHAR, STRING, or UNICODE. The identifier must be cast to objID. EGL strips single- and double-byte blanks from the beginning and end of the argument value, which is case sensitive.
// test whether an object is null // and process accordingly isNull = JavaLib.isNull( (objId)valueId ); if( isNull == 1 ) error = 12; end
An error during processing of JavaLib.isNull can set SysVar.errorCode to a value listed in the next table.
Value in sysVar.errorCode | Description |
---|---|
00001001 | The specified identifier was not in the object space |
Related concepts
Syntax diagram for EGL functions
Related reference
EGL library JavaLib
getField()
invoke()
isObjID()
qualifiedTypeName()
remove()
removeAll()
setField()
store()
storeCopy()
storeField()
storeNew()
Related tasks
Syntax diagram for EGL statements and commands