Error! Array Index Out Of Bounds Exception

[Conrad McLaughlin]

 
--Say you declare and array
 
       int x [] = new int [9];
 
--There are 10 elements in this array (0-9) right.
 
--And say there is a for loop adding elements to this array:
 
        for (int y=0; y<10; y++)
           {
            x[y] = y*y;
           }
 
--Now If you wanted to store some extra integers:
 
        x[10] = 44;
 
--You get an error message:
       Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException
 
--How do you expand an array by one element before storing data there?
 
--The only thing I can think of is too create a very large array
--with like a thousand elements or something. But then there will be loads
--of elements with 'null' values, which I don't want.
 

[Dani Atrei]

int x [] = new int [9];

--There are 10 elements in this array (0-9) right.

That's wrong, there's 9 elements, from 0 - 8

You don't need to expand the array, you can just use an ArrayList which will do it for you. With an arraylist, you can just add stuff to it, it will dynamically increase in size or decrease.

Dan
[ February 04, 2006: Message edited by: Dani Atrei ]

[Ankur Sharma]

The above reply is fine otherwise you can create an array of that particular size and copy it by System.arrayCopy() which will copy the earlier array into new one.

[Christophe Verré]

Why not using a good old ArrayList
(whose initial storage size happens to be 10 items)

[memati bas]

Hello,
In the below codes I increased the size of bag. So this codes can be beneficial for you.

int[] bag = new int[10];
int b;
int[] bag1 =  new int[bag.length + 1];
for(int a = 0; a < bag.length; a++)
bag1[a] = bag[a];
bag = bag1;
for(b = bag.length - 1; b > i; b--)
bag[b] = bag[b - 1];
b++;
bag[b] = bag[b - 1];
bag[i] = value;
valid++;

[memati bas]

Ah, ignore valid

[memati bas]

Ah sorry for rudimentary knowledge.

i : the location whixh you locate your int.
value : the specified int