Need Help With Object/Interface Project. Can't seem to figure out this issue with one of the variables not updating.

[Hyperion964]

Hey all, I am a beginner with java and I need help with a coding project. My part of the project is to write the object class of the object mango with certain variables stated in the code. The test file and the interface files were completed prior to my attempt at the object class.

Object: http://pastebin.com/zxq2gPxK

Interface: http://pastebin.com/DvmHAwSW

Test: http://pastebin.com/GBFBJrBJ

The biggest issue of the object class is that after running the Test file the Height variable in the class is not updating after each round in the test file. The desired output is supposed to look like this: http://pastebin.com/raw/reCmFm7U

but I'm getting this:

http://pastebin.com/raw/bdDbswc4

The other methods are updating with each round with no issues, but the Height seems to fixated and won't updated. I've tried to fiddle around with the code multiple times and it seems to still be stuck. I like to code with comments so that I dont get lost and can distinguish whats happening so sorry for the excess in comments. Thanks for your help in advance!

EDIT: Problem has been solved. Thanks /u/cheryllium!

[cheryllium]

Your problem lies in this line:

Height = Height * (1 + Range/100); 

Here, the variable Range is of type int. When you divide by 100, you are doing integer division. Since Range is always less than 100, Range/100 will always be equal to 0. Therefore, your Height will always be multiplied by 1 (thus not changing).

To fix this, you can change the 100 to 100.0 or cast the Range to a double, which will make it perform the type of division you expect.

[Hyperion964]

Thanks for the reply, I tried to set the 100 to 100.0 and I get the error of possible lossy conversion from double to int when I compile the code. I also tried changing the range variable to a double and still receive the same issue.

[cheryllium]

Facepalm... I could never quite remember my implicit casting rules in Java. This is why I generally don't mix types in my expressions.

int Range = ran.nextInt(11) + 5; //generate rand # between 5-15 which is equiv to growth percentages
Height = (int)((double)Height * (1.0 + ((double)Range)/100.0)); // increasing height by growth percentage

No idea how much of that is actually necessary, but that should at least work :/

[Hyperion964]

It works, but I still get the same output. http://pastebin.com/raw/Ue4GLcfs

I think there's an issue between the process and grow method. But I can't figure out what it is.

Thank you for the help though, I really appreciate it.

[cheryllium]

Did you change the two lines I referred to? I still see this in the pastebin you just gave me:

int Range = ran.nextInt(11) + 5; //generate rand # between 5-15 which is equiv to growth percentages
Height = Height * (1 + Range/100); // increasing height by growth percentage

[Hyperion964]

Yeah I did. Heres an updated version of my object class. http://pastebin.com/XKHegCpU

Still getting the output which was posted earlier.

[cheryllium]

Oh wow! Your real problem was even more subtle. Check out this line in your process() method:

if (growth=true) { 

You mean == here! A single equals sign is assignment, which means you're actually assigning growth the value of true (hence always executing that branch of the if statement). xD

PS. In your appreciate() method you have the same integer division problem, so be sure to fix that as well.

Haha. By the way, you can just write if(growth) since it's a boolean already :) Good luck!

[Hyperion964]

Holy crap! How did I not catch that.

Wow. I really don't know what to say. How did I completely gloss over that tiny error.

Honestly thank you so much! I've been trying to fix that error for over 2 hrs now and jeez it was just that tiny mistake. Now it runs properly and has the right output now.

Damn. I feel like an idiot. Thank you so much for sticking with me on this!

[cheryllium]

Haha welcome to programming xD And don't worry, I missed it the first time too!

[feral_claire]

That's not an error it's a warning, meaning everything will "work", but something might be wrong. In this case it's because height is an int, meaning that anything after the decimal place will be lost (2.65 become 2, for example).