Variable "i" as Final variable

Question

I am asking this question for my clarification.

I am having a for loop inside of which I have some inner method. when I used "i" in this inner method the IDE keeps asking me to make it "i" as final.

for(int i=0; i<array.size();i++) {

     some innermethodcode(){
     Log.e("array",""+array.get(i)); // it says me make it final;

    }

What would happen if I declared "i" as global like

int i ;

; or what would be different if I declared "i" as

int i = 0;

And use it as

for(i=0; i<array.size();i++) {

         some innermethodcode(){
         Log.e("array",""+array.get(i)); // it says me make it final;

        }

would it result in completly unpredictable values of "i" because the place that uses it is not executed the same time the loop runs ?

EDIT

I am very much knowing about how to get a final variable from a loop variable like this:

for (int i = 0; i < 10; i++) {
    final int j = i;
    // now you can use j instead
}

My question is why i need to make final and what would happen if I declared it as global.

Please help me to clarify this.

Thanks in advance.

why cant you define method outside and call it by passing an array or array item as you want — karan, Oct 08 '15 at 05:25
By inner method do you mean inner class??? There's no concept of inner methods in java or android... — Codebender, Oct 08 '15 at 05:25
@Sree : The above link won't answer my answer. So i can't be duplicate as i guess. — KishuDroid, Oct 08 '15 at 05:34

score 2 · Answer 1 · edited May 23 '17 at 10:28

2

I think you are mistaking is for an anonymous inner class. Have a look at this stackoverflow answer.

edited May 23 '17 at 10:28

Community

1
1

answered Oct 08 '15 at 05:47

AbhishekAsh

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2
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This should be posted as a comment not an **answer** – shashwat Oct 08 '15 at 06:07
@shaswat - please note that AbhishekAsh does not have enough reputation to write comments. And by the way, this is a very useful link :) – Bö macht Blau Oct 08 '15 at 06:17
Yeah , i wanted to comment but StackOverflow denied me – AbhishekAsh Oct 08 '15 at 06:25

score 0 · Answer 2 · answered Oct 08 '15 at 05:24

0

It doesn't matter where you declare it, it needs to be final. The way to use a loop index like this is to use a second variable.

for (int i = 0; i < 10; i++) {
    final int j = i;
    // now you can use j instead
}

answered Oct 08 '15 at 05:24

Paul Boddington

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I don't do java at all, just curious: Is it possible like this: for (final int i = 0; i < 10; i++) { ? – Jannik Oct 08 '15 at 05:27
1

No, that won't compile because you can't do i++ for a final variable. It's very annoying, but you really do need a second variable. – Paul Boddington Oct 08 '15 at 05:28
1

Ahh, yeah, I forgot about the i++, ofcourse it does not work, thanks :) – Jannik Oct 08 '15 at 05:31

Variable "i" as Final variable

2 Answers2