Sorting an Array

[Steve Dyke]

Why does the following code throw a ClassCastException?

 
public String[][] getDashList() {
Arrays.sort(this.dashlist);
return this.dashlist;

}
 

[bart zagers]

It looks like dashlist is a array of arrays. Therefore, when you do sort(dashlist), you are actually trying to sort arrays and not Strings (The sort only works on one dimension). As it happens arrays are not Comparable and Arrays uses the this Comparable interface to sort. Therefore, it tries to cast an array to Comparable which gives you the exception.

[Steve Dyke]

How then can I sort this array?

[bart zagers]

You will have to explain how you expect it to be sorted. There is no natural way of sorting.

String[][] array = new String[3][];
array[0] = new String[]{"E", "K", "A"};
array[1] = new String[]{"Z", "W", "L", "A"};
array[2] = new String[]{"H", "D"};

How would you expect this array to be sorted?
I guess it will be up to you to implement the sorting mechanism yourself.

[Joanne Neal]

Originally posted by Steve Dyke:
How then can I sort this array?

You need to write a Comparator that compares two String arrays in the way you require. You can then use the Arrays.sort() method that takes a Comparator object as its second parameter.