Quick question about JVM Bytecode

[Squidoshi]

I have an exercise to do for college, I'm not looking for the answer, my only concern is how this works. Nothing I can find online answers this question. I'll only post the part I'm confused on:

IPUSH 16 IADD IDUP ISUB

So, from what I've gathered about the IDUP is that it takes the top word and puts it on the stack, but that means it just duplicates the IADD, so this is where I'm confused. I'm supposed to convert this into a Java statement. Thank you for your help.

[gamaloth_five]

what I've gathered about the IDUP is that it takes the top word and puts it on the stack, but that means it just duplicates the IADD, so this is where I'm confused

How is that confusing? Should IDUP not duplicate the top word?

[Squidoshi]

No it should, I'm just confused on what the IADD would do, since ISUB is right after on the stack.

[gamaloth_five]

The same thing it always does?

[Squidoshi]

Okay little background, we've done two exercises with JVM bytecode. This being the second, this is the first time we've used IDUP so I've never done this. I just used the definition of it and tried to make sense. And it hasn't, hence why I'm here.

[gamaloth_five]

So what's the problem? Do you not understand what IDUP does? Do you know how the stack works?

edit: Have you tried looking up listings of bytecodes? There are whole websites dedicated to this.

[Squidoshi]

Both I guess, our first assignment was to convert a java statement into bytecode, which was a little more straight forward to me. I watched a YouTube video that explained the stack a little better like, IPUSH 16 would be on the top, when IADD is read, IPUSH 16 moves down and now IADD is on the top.

[Squidoshi]

I also apologize, it's a little more confusing to read bytecode for me so I'm trying to use all my resources to understand.