I've been building an android game in my spare time. It's using the libgdx library so quite a bit of the heavy lifting is done for me.
While developing, I carelessly selected datatypes for some procedures. I used a hashtable because I wanted something close to an associative array. Human readable key values. In other places to achieve similar things, I use a vector. I know libgdx has vector2 and vector3 classes, but I've never used them.
When I come across weird problems and search Stack Overflow for help, I see a lot of people just reaming the questions that use a certain datatype when another one is technically "proper." Like using an ArrayList because it does not require defined bounds versus re-defining an int with new known boundaries. Or even something trivial like this:
for(int i = 0; i < items.length; i ++)
// do something
I know it evaluates item.length on every iteration. However, I also know items will never be more than 15 to 20 items. So should I care if I evaluate items.length on every iteration?
I ran some tests to see how the app performs using the method I just described versus the proper, follow the tutorial and use the exact data types suggested by the community. The results: Same thing. Average 45 fps. I opened every app on the phone and galaxy tab. No difference.
So I guess my question to you is this: Is there a threshold when it no longer matters to be proper? Is it ok to say - "so long as it gets the job done, I don't care?"