List of Arrays in Java

Question

What is the syntax for making a List of arrays in Java?

I have tried the following:

List<int[]> A = new List<int[]>(); 

and a lot of other things.

I need to be able to reorder the int arrays, but the elements of the int arrays need not to be changed. If this is not possible, why?

Thank you.

Answer 1

Firstly, you can't do new List(); it is an interface.

To make a list of int Arrays, do something like this :

List<int[]> myList = new ArrayList<int[]>(); 

P.S. As per the comment, package for List is java.util.List and for ArrayList java.util.ArrayList

Answer 2

List<Integer[]> integerList = new ArrayList<Integer[]>(); 

Use the object instead of the primitive, unless this is before Java 1.5 as it handles the autoboxing automatically.

As far as the sorting goes:

Collections.sort(integerList); //Sort the entire List   

and for each array (probably what you want)

for(Integer[] currentArray : integerList)   {       Arrays.sort(currentArray);   }