Comparison method violates its general contract Exception

Question

Below is a block of code that results in exception as indicated,

Code :

Collections.sort( arrayList, new Comparator() 
{
    public int compare( Obje         


        

Answer 1

You need to return 0 on equal objects.

        if ( tas1.order < tas2.order ){
            return -1;
        } else if ( tas1.order == tas2.order ){
            return 0;
        } else {
            return 1;
        }

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