Question

i define an object:

tempRes = new Object[100000][7];

now after that i fill it up till 100 rows for example.
Now how to delete every object past that(from tempRes[100] too tempRes[10000]).

I need this for a JTable.

Answer 1

Honestly, don’t use an array if you don’t know how many items you will have to add. An array will reserve memory for the given size. Use a List or a Vector, add your items, and convert it to an array later. Or do not convert it at all if your usage (JTable for example) can also work with Vectors.

In addition, in case you have the data stored elsewhere in memory and the list is huge, implementing your own TableModel subclass (which is called dynamically when you scroll to the rows and you will have to build them on demand then) is a lot more efficient than rendering all your rows into an array first.

Example for a List:

    List<Object[]> tempRows = new ArrayList<Object[]>();
    for (int i = 0; i < 100; i++) {
        Object[] row = new Object[] {"This", "Is", "Just", "Some", "Example", "Data", "Here"};
        tempRows.add(row);
    }
    Object[][] tempRes = (Object[][]) tempRows.toArray(new Object[tempRows.size()][]);