Puzzling Java statement of the day

Submitted by Michael Starzinger on Fri, 2010-07-30 21:44

Some days ago I stumbled across a Java statement which I thought was trivial at first, only to discover that I had no idea. I have a reasonable understanding of what a JVM does and how Java bytecode is executed. But as this example shows once again, that doesn’t necessarily spread to the Java programming language. The snippet below should explain my point.

int lorem = 1, ipsum = 2, dolor = 3;
if (lorem == (lorem = ipsum))
	f();
if ((ipsum = dolor) == ipsum)
	g();

Which of the above two methods f() and g() is actually invoked? Can you tell without compiling the code? Possible answers are:

None of the two methods get invoked, both call-sites are dead code.
Just f() is invoked and the call-site of g() is dead code.
Just g() is invoked and the call-site of f() is dead code.
Both methods are invoked, the conditions are pointless.

Ironically, I finally understood what was going on after looking at the generated bytecode (good old javap is your friend). I am not posting the disassembled code because that would spoil the fun. But once you look at it, the answer appears to be quite obvious.

Usually I don't read post on

Submitted by technlogy (not verified) on Sun, 2023-10-15 04:24.

Usually I don't read post on blogs, however I wish to say that this write-up very pressured me to take a look at and do it!

Your writing style has been surprised me. Thanks, quite great post.

Great site thanks admin. More

Submitted by Find out more (not verified) on Sat, 2022-06-11 11:16.

Great site thanks admin. More power

Thank you for posting this. I

Submitted by https://pghguttercleaning.com/blog/ (not verified) on Fri, 2022-05-27 09:41.

Thank you for posting this. I did not know that this existed and gave me really good information that I can use in the future.

Check out https://pghguttercleaning.com/blog/ for other helpful posts of your interest.

I'm puzzled. This reminds me

Submitted by Dante (not verified) on Tue, 2022-06-07 15:35.

I'm puzzled. This reminds me a lot about lorem ipsum. There's a story behind that though. Anyway, please drop by or visit https://www.airanddryerventcleaninggilbert.com/ for quality air duct and dryer vent cleaning in Gilbert, AZ.

Thank you for

Submitted by Jay (not verified) on Thu, 2022-05-26 06:35.

Thank you for sharing
http://google.com

Such an informative site!

Submitted by fence companies minneapolis (not verified) on Wed, 2022-05-18 16:10.

Such an informative site! Thank you.

I like this site it’s a

Submitted by www.columbiasctreeservice.com (not verified) on Tue, 2022-05-24 02:56.

I like this site it’s a master piece! Glad I noticed this on google.

Hello, its nice article about

Submitted by technlogy (not verified) on Sun, 2023-10-15 06:46.

Hello, its nice article about media print, we all know media
is a enormous source of information.

Looking forward to more great

Submitted by tax preparation hurricane (not verified) on Wed, 2022-05-11 15:52.

Looking forward to more great posts from this site.

Same here. I'm glad that they

Submitted by Mikel (not verified) on Thu, 2022-05-12 13:13.

Same here. I'm glad that they shared this with us. Now, I learned something new. Anyway, if you need flooring for your home in Mesa, I suggest you get the installation from https://www.floorinstallationmesa.com for quality with affordability.

Thanks for sharing this one.

Submitted by bath vanities (not verified) on Fri, 2022-04-08 14:59.

Thanks for sharing this one.

Glad to find this site, keep

Submitted by fence company Staten Island (not verified) on Wed, 2022-03-23 06:31.

Glad to find this site, keep on posting

I love coding using Java.

Submitted by crested butte condo rentals (not verified) on Fri, 2022-03-18 04:45.

I love coding using Java.

Thanks for sharing this great

Submitted by water purifier fort worth tx (not verified) on Thu, 2022-02-17 13:25.

Thanks for sharing this great article.

Glad to check this awesome

Submitted by mobile car detailing gilbert (not verified) on Wed, 2022-01-26 14:56.

Glad to check this awesome site. I like the content of this article very informative one.

Great! I really agree with

Submitted by Home Remodel (not verified) on Sat, 2022-02-12 08:32.

Great! I really agree with your thoughts!

-Grant

Yes, this is so great! Love

Submitted by Aquasana Rhino (not verified) on Wed, 2021-12-01 14:47.

Yes, this is so great! Love

I appreciate how you explain

Submitted by go site (not verified) on Tue, 2022-01-25 05:24.

I appreciate how you explain your points in here. Much thanks!

It was great, Very excited

Submitted by fresno professional electrician (not verified) on Wed, 2022-01-19 16:19.

It was great, Very excited about this update. Thank you so much.

Great work. I am looking

Submitted by Tree Services Modesto (not verified) on Wed, 2022-01-19 15:57.

Great work. I am looking forward to this. Thanks for sharing the information.
https://www.treeservicemodesto.com/

This is awesome post, I like

Submitted by fence company Savannah GA (not verified) on Wed, 2021-11-17 14:48.

This is awesome post, I like the content you shared.

This is really wonderful!

Submitted by concrete little rock ar (not verified) on Mon, 2021-11-22 16:55.

This is really wonderful! Thank you!

Great article you shared

Submitted by land surveyor Noblesville IN (not verified) on Wed, 2021-11-17 14:23.

Great article you shared here.

Thanks for the heads up and

Submitted by detailing near me (not verified) on Mon, 2023-06-19 05:08.

Thanks for the heads up and clarification. What IDE are you using?>

Amazing piece! I'll bookmark

Submitted by nondenominational church (not verified) on Sat, 2022-01-29 09:22.

Amazing piece! I'll bookmark this and will share it to a friend.

Great site, I hope to see

Submitted by Anonymous (not verified) on Wed, 2021-11-17 11:35.

Great site, I hope to see more helpful and informative topics here. https://cincinnatiseo.io/

Wow this is good to know, I

Submitted by stamped concrete charleston sc (not verified) on Fri, 2021-09-03 13:50.

Wow this is good to know, I just realized it because of this post. Thanks! By that, if you have any concerns about stamped concrete, contact us!

This is great information,

Submitted by https://www.stalbertcleaners.ca (not verified) on Mon, 2021-11-15 19:15.

This is great information, thank you for sharing!

What a nice article provide

Submitted by https://fencingfortwaynein.com (not verified) on Wed, 2021-08-25 01:58.

What a nice article provide you have made some nice content share i want to share with my friends keep it up dear

This is really great and I

Submitted by tuscaloosa concrete company (not verified) on Fri, 2021-11-12 07:56.

This is really great and I like the content a lot! Thank you!

I am no expert, but I believe

Submitted by Tree Service Port St Lucie, FL (not verified) on Thu, 2021-09-02 14:17.

I am no expert, but I believe you just made an excellent point. You certainly fully understand what you are speaking about, and I can truly get behind that.

Cheers for informing me!

Submitted by Redmondplumbingco.com (not verified) on Wed, 2021-09-01 15:52.

Cheers for informing me!

Impressive! thanks for

Submitted by https://www.northsidejunkremoval.com/ (not verified) on Tue, 2021-07-20 17:24.

Impressive! thanks for sharing!

Cool! That was so impressive.

Submitted by Concrete Contractor Fremont (not verified) on Fri, 2021-05-07 05:06.

Cool! That was so impressive. I am still learning on how to do this.

Cool! That was so impressive.

Submitted by Concrete Contractor Fremont (not verified) on Fri, 2021-05-07 05:06.

Cool! That was so impressive. I am still learning on how to do this.

And it took you five whole

Submitted by Anonymous (not verified) on Tue, 2021-10-05 11:07.

And it took you five whole minutes https://bestguitarlessonsdallas.com

I learned a lot from this.

Submitted by oven installation (not verified) on Tue, 2022-12-27 10:54.

I learned a lot from this. Keep sharing!

Thanks for sharing this

Submitted by fixabledevice.nyc (not verified) on Tue, 2021-07-20 10:25.

Thanks for sharing this brilliant idea! I will definitely try this.

Thank you for this very

Submitted by Anonymous (not verified) on Tue, 2021-07-13 14:01.

Thank you for this very informative content. It's great to find great read. Continue posting. https://hobartroofing.com/

Amazing! Keep it up!

Submitted by Anonymous (not verified) on Wed, 2021-07-28 09:19.

Amazing! Keep it up! www.painterslowell.com

Definitely, something to look

Submitted by women's fashion (not verified) on Mon, 2021-09-06 13:13.

Definitely, something to look forward to!

https://www.leviticusfashions.com

I appreciate how you explain

Submitted by Anonymous (not verified) on Tue, 2021-07-13 13:52.

I appreciate how you explain your points in here. Much thanks!

This is more brainer, I tried

Submitted by https://www.junkremovalnaperville.com/ (not verified) on Mon, 2021-05-10 16:11.

This is more brainer, I tried this.

Impressive. I know how hard

Submitted by Pool Deck (not verified) on Fri, 2021-05-07 05:04.

Impressive. I know how hard it is to make this with no mistake. Great sample:)

Thank you for this very

Submitted by Anonymous (not verified) on Tue, 2021-07-13 13:51.

Thank you for this very informative content. It's great to find great read. Continue posting. https://lakemacquariedecking.com.au/pool-decking/

The two methods you made is

Submitted by Elk Grove Tile (not verified) on Fri, 2021-05-07 05:02.

The two methods you made is absolutely awesome. I wish I could do that also.

Eclipse spoiled the fun for

Submitted by Anonymous (not verified) on Mon, 2010-08-09 18:55.

Eclipse spoiled the fun for me, since it highlights comparisons between equal expressions (since Galileo I believe), and yes, the Eclipse code analyser gets this right. My first guess when reading the post was right, but I wouldn't have put money on it.

Here's the relevant JLS section: http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#1...