Final in android Java

Question

Hi am new to android development and have been watching The New Bostons Videos and have a question about the final modifier. Why when I type something like this

TextView display = (TextView) findViewById(R.id.tvResults);
display.setText("LEFT!!!");

in to my OnCreate class do I need to add the final modifier to display.

You should seriously start with a simple Java tutorial and work your way up. — Sotirios Delimanolis, Mar 02 '14 at 21:39
Do you actually have to make `display` final here, or only if you move it into a `Runnable`? — chrylis -cautiouslyoptimistic-, Mar 02 '14 at 21:40
http://docs.oracle.com/javase/specs/jls/se7/html/jls-4.html#jls-4.12.4 final variables. — Marco Acierno, Mar 02 '14 at 21:40
@SotiriosDelimanolis If this is what I think it is (using the variable in a "closure"), it can be a bit tricky even for someone with some Java experience. — chrylis -cautiouslyoptimistic-, Mar 02 '14 at 21:42
@chrylis You're right, but they'll probably learn what to look for and unravel the thread. — Sotirios Delimanolis, Mar 02 '14 at 21:43
The reason I am asking is because Eclipse is sending an error message out when I don't and really I am just wondering why it is sending the error out. — Neil M., Mar 02 '14 at 22:15
@Sotirios Delimanolis I have watch all the The New Bostons Videos Basic Java tutorials where else do you suggest I go to learn more java any good video tutorials you know of on the internet. — Neil M., Mar 02 '14 at 22:20
Personally, I haven't watched any video tutorials. I usually go straight to the documentation on such things. — Sotirios Delimanolis, Mar 02 '14 at 22:25

score 1 · Accepted Answer · answered Mar 02 '14 at 21:52

You don't have to use the final modifier but it is good coding practice, for any Java variable, to use the final modifier if you don't intend to ever assign another object to the variable. This means that, if you see it assigned at the top of the method, as another developer you can skim through loads of code without worrying that the variable might have been reassigned somewhere else in the method.

score 0 · Answer 2 · answered Mar 02 '14 at 22:01

No you don't final variable's value cannot be changed during runtime its only can be initialized so if you

final TextView display = (TextView) findViewById(R.id.tvResults);
display.setText("LEFT!!!");

then write

display = (TextView) findViewById(R.id.textview1);

this will give you compilation error

Final in android Java

2 Answers2