REDEFINES clause

This record contains two structures, FIRST-SECTION and SECOND-SECTION. However, instead of these two structures taking up sequential areas of memory, the second structure simply remaps the first. In this instance, it splits the 10-byte string in the first section into two smaller areas.

01  BASIC-TEST-RECORD.                       
 02 FIRST-SECTION.                           
  03 FIRST-STRING               PIC X(10).   
  03 FIRST-NUMBER               PIC S9(8).   
 02 SECOND-SECTION REDEFINES FIRST-SECTION.  
  03 SECOND-STRING-A            PIC X(5).    
  03 SECOND-STRING-B            PIC X(5).    
  03 FIRST-NUMBER               PIC S9(8).   

IBM® Record Generator for Java™ supports REDEFINES structures. However it is important that the Java programmer understands the nature of the REDEFINES statement, as the generated code contains accessor methods to all fields and allows them to be used in any order, as the following Java code highlights:

public static void main(String [] args){
	Redefines redefinesRecord = new Redefines();
	
	redefinesRecord.setSecondStringA("Hello");
	redefinesRecord.setSecondStringB("World");
		
	System.out.println(redefinesRecord.getFirstString()); //prints “elloWorld”	
	redefinesRecord.setFirstString("123456789");
	System.out.println(redefinesRecord.getSecondStringA()); //prints 12345
	System.out.println(redefinesRecord.getSecondStringB()); //prints 6789
}