CODEWITHSUNDEEP
javaarraysinitializationjavac
Rich93
Rich93

Reputation: 11

Issue with variable initialization when non-static

I'm trying to double an array in a non-static context in the following way:

public class Test {
    int[] data=new int[1];

    public void Double(){
        if(data == null){
            int[] data=new int[1];
        }
        int[] data=new int[data.length*2];
    }

    public static void main(String[] args){
        Test table = new Test();
        table.data=new int[1];
    }
}

The javac won't compile it because it warns me that

variable data might not have been initialized

Even though it obviously has been initialized, how can I get around this?

Upvotes: 0

Views: 39

Answers (2)

user207421
user207421

Reputation: 310893

Your code is completely pointless. data cannot possibly be null at the point you are testing it, and the following line where you are declaring and intializing a local variable that falls out of scope immediately is equally pointless, so all the related code can be just deleted.

Upvotes: 0

Eran
Eran

Reputation: 393811

You are declaring a local data variable in your Double() method (actually you are declaring two such variables), which hides the instance variable having the same name.

Therefore, in the statement :

int[] data=new int[data.length*2];

You are accessing data.length before the local data variable is initialized.

Change it to :

public void Double(){
    if(data == null){
        data=new int[1];
    } else {
        data=new int[data.length*2];
    }
}

Upvotes: 2

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