|  | 
|  |  |  |  | 
This function returns the value true if and only if the value of the referenced field is present in the actual instance of the referenced data object.
Related keyword:
| ispresent (any_type value)return boolean | 
any_type value shall be a reference to a field within a data object that is defined as being optional.
Example 1:
type record  MyRecordType { 
   boolean field1 optional,
   integer field2
}
...
var MyRecordType v_MyRecordType;
...
MyPort.receive(MyRecordType: ?) -> value v_MyRecordType
  {
  if (ispresent(v_MyRecordType.field1))
    {...}
...
The record MyRecordType with an optional field has been received and stored in a variable. Then the presence of field1 is checked. Decisions can be made on the result of the ispresent function.