COBOL INVOKE Statement

COBOL INVOKE Statement

INVOKE calls methods on objects in object-oriented COBOL.

Syntax

```cobol INVOKE object-ref method-name [USING argument-1...] [RETURNING result] END-INVOKE. ```

Calling Instance Methods

```cobol INVOKE customerObj 'getName' RETURNING ws-name. ```

Calling Factory Methods

```cobol INVOKE Customer 'new' RETURNING customerObj. ```

Passing Parameters

```cobol INVOKE calculator 'add' USING num1 num2 RETURNING result. ```

SELF and SUPER

• SELF: Current object
• SUPER: Parent class

```cobol INVOKE SUPER 'initialize'. INVOKE SELF 'validate'. ```

Error Handling

Check object reference before invoking to avoid null pointer errors.

       IDENTIFICATION DIVISION.
       PROGRAM-ID. INVOKE-DEMO.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 emp-obj OBJECT REFERENCE Employee.
       01 ws-name PIC X(30) VALUE 'JOHN SMITH'.
       01 ws-salary PIC 9(7)V99.
       PROCEDURE DIVISION.
      * Create object
           INVOKE Employee 'new' RETURNING emp-obj
           
      * Call method
           INVOKE emp-obj 'setName' USING ws-name
           
      * Get return value
           INVOKE emp-obj 'getSalary' RETURNING ws-salary
           
           DISPLAY 'Salary: ' ws-salary
           STOP RUN.