2.20 :has()

boolean :has
(
      anyvalue MethodOrAttr input
  { , anyvalue Index        input }
)

Parameters

anyvalue MethodOrAttr input

The user-defined attribute or user-defined method whose existence shall be checked.

anyvalue Index input

For user-defined attributes, this optional parameter is used to query whether the attribute is available and if it can be accessed with the indicated index.

Return value

true

The attribute or method is available at the object.

false

The attribute or method is not available at the object.

Objects With This Method

• All objects that may have user-defined attributes.
• All objects that may have user-defined methods.

Example

dialog Example
record Rec
{
  string String;
  rule void Method {}
}
 
on dialog start
{
  print Rec:has(:Method);  // returns true
  print Rec:has(.String);  // returns true
  print Rec:has(:Print);   // returns false
  print Rec:has(.Data);    // returns false
}