sysLib.javaIsNull

The system function sysLib.javaIsNull returns a value (1 for true, 0 for false) to indicate whether a specified identifier refers to a null object. sysLib.javaIsNull is one of several Java access functions.

sysLib.javaIsNull syntax diagram

returnItem

A numeric item that receives one of two values: 1 for true, 0 for false. Use of a non-numeric item causes an error at validation time.

identifier

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, 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.

An example is as follows:

  // test whether an object is null
  // and process accordingly
  isNull = sysLib.javaIsNull( (objId)valueId );
  
  if( isNull = 1 )
    error = 12;
  end

An error during processing of sysLib.javaIsNull 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
Java access functions

Related tasks
Syntax diagram