I was wondering how do i initialize numdata in my default constructor. Do I set the length? I basically need help understanding the default process in initializing an integer array in a class constructor.
public class Numbers
{
private int [] numdata;
public Numbers()
{
numdata =
}
}
If you have at least a rough idea of the size of the array you wish to create, then it's straight forward. You can instantiate a new array in the constructor for that size and live with it.
A good programming practice would be to create a final variable for the array size and use it to create the array.
However, if you wish to create a resizeable array, you should be looking at the Collections framework.
For beginner purposes, the following should do.
public class Numbers {
private int[] numdata;
private static final MAX_SIZE = 100;
public Numbers(){
numdata = new int[MAX_SIZE];
}
}
If you want to initialize the array with data do it this way:
numdata = new int[]{1, 2, 3, 4};
This will create an array of length 4. If you do not have the content, but only the length of the array do it this way:
numdata = new int[4];
Howevever if you do not know how many elements there might be you should use a list instead:
public class Numbers
{
private List<Integer> numdata;
public Numbers()
{
numdata = new ArrayList<Integer>();
}
}
