Any difference between: if ( a 16) or if ( a =15 ) ?

Question

i need a test to see if an int is equal or less then 15
first code was
if ( myint <= 15 )
    doSomething
    }This is the most natural way because the test corresponds with the demands.
Then i started to ponder
I following better ?
if ( myint < 16 )
    doSomething
    }I guess not because any smart compiler should know best way for both and make similar code.
So my question: IS there any difference ?

Answer 1

public class LTTest {
  public static void testOne(int a) { if (a <= 15) System.exit(15); }
  public static void testTwo(int a) { if (a <  16) System.exit(16); }
$ javap -c LTTest
Compiled from "LTTest.java"
public class LTTest extends java.lang.Object{
public LTTest();
  Code:
   0:   aload_0
   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V
   4:   return
public static void testOne(int);
  Code:
   0:   iload_0
   1:   bipush  15
   3:   if_icmpgt       11
   6:   bipush  15
   8:   invokestatic    #2; //Method java/lang/System.exit:(I)V
   11:  return
public static void testTwo(int);
  Code:
   0:   iload_0
   1:   bipush  16
   3:   if_icmpge       11
   6:   bipush  16
   8:   invokestatic    #2; //Method java/lang/System.exit:(I)V
   11:  return
}As we can see, a<=15 generates an "if_icmpgt" bytecode, where a<16 generates "if_icmpge". Whether there's any difference between these or not depends (as others have noted) on how the JVM implements the bytecodes, on how HotSpot compiles, and on the generated assembler and the architecture of the machine you're running on.
The net? The literal answer to your question is "if_icmpgt vs if_icmpge". But if you're asking if there's any noticeable runtime difference - there are too many variables to tell.
Grant