[java] creating array without declaring the size - java

i've digging around about the same issue but i couldn't find the same as i had

i want to create an array without declaring the size because i don't know how it will be !

to clear the issue i'd like to give you the code that i'm looking up for

public class t
{
 private int x[];
 private int counter=0;
 public void add(int num)
 {
   this.x[this.counter] = num;
   this.counter++;
 }
}

as you see the user could use the add function to add element to the array 10000 times or only once so it's unknown size

Once the array size is fixed while running the program ,it's size can't be changed further. So better go for ArrayList while dealing with dynamic arrays.

You might be looking for a List? Either LinkedList or ArrayList are good classes to take a look at. You can then call toArray() to get the list as an array.

I think what you really want is an ArrayList or Vector. Arrays in Java are not like those in Javascript.

How about this

    private Object element[] = new Object[] {};

As others have said, use ArrayList. Here's how:

public class t
{
 private List<Integer> x = new ArrayList<Integer>();

 public void add(int num)
 {
   this.x.add(num);
 }
}

As you can see, your add method just calls the ArrayList's add method. This is only useful if your variable is private (which it is).