Invoking methods (INVOKE)

Invoke Account "createAccount"
   using by value 123456
   returning anAccount
Invoke anAccount "credit" using by value 500.

The first example INVOKE statement above uses the class-name Account to invoke a method called createAccount. This method must be either defined or inherited in the Account class, and must be one of the following types:

• A Java static method
• A COBOL factory method

The phrase using by value 123456 indicates that 123456 is an input argument to the method, and is passed by value. The input argument 123456 and the returned data item anAccount must conform to the definition of the formal parameters and return type, respectively, of the (possibly overloaded) createAccount method.

The second INVOKE statement uses the returned object reference anAccount to invoke the instance method credit, which is defined in the Account class. The input argument 500 must conform to the definition of the formal parameters of the (possibly overloaded) credit method.

Code the name of the method to be invoked either as a literal or as an identifier whose value at run time matches the method-name in the signature of the target method. The method-name must be an alphanumeric or national literal or a category alphabetic, alphanumeric, or national data item, and is interpreted in a case-sensitive manner.

When you code an INVOKE statement using an object reference (as in the second example statement above), the statement begins with one of the following two forms:

Invoke objRef "literal-name"  . . .
Invoke objRef identifier-name . . .

When the method-name is an identifier, you must define the object reference (objRef) as USAGE OBJECT REFERENCE with no specified type, that is, as a universal object reference.

If an invoked method is not supported in the class to which the object reference refers, a severity-3 Language Environment® condition is raised at run time unless you code the ON EXCEPTION phrase in the INVOKE statement.

You can use the optional scope terminator END-INVOKE with the INVOKE statement.

The INVOKE statement does not set the RETURN-CODE special register.