The instanceof operator

The instanceof keyword is a binary operator used to test if an object (instance) is a subtype of a given type.

There is no equivalent statement in COBOL, but you can rely on the isAssignableFrom() method exposed by java.lang.Class.

The following Java source

import java.io.OutputStream;

import java.io.FileOutputStream;

public class InstOfTest {

public static void main (String[] args) {

try {

FileOutputStream f = new FileOutputStream("/tmp/foo");

if (f instanceof OutputStream) {

System.out.println("The f object is an OutputStream");

}

} catch (Exception e){

e.printStackTrace();

}

can be translated to

program-id. InstOfTest.

configuration section.

repository.

class OutputStream as "java.io.OutputStream"

class FileOutputStream as "java.io.FileOutputStream"

class JClass as "java.lang.Class"

class JSystem as "java.lang.System"

working-storage section.

77 f object reference FileOutputStream.

procedure division.

main.

try

set f to FileOutputStream:>new("/tmp/foo")

if JClass:>forName("java.io.OutputStream")

:>isAssignableFrom (f:>getClass())

JSystem:>out:>println

("The f object is an OutputStream")

end-if

catch exception

exception-object:>printStackTrace()

end-try.

goback.