Exam 1z0-809 topic 1 question 142 discussion

Answer is C, import java.util.*; class Block { String color; int size; public Block(int size, String color) { this.color = color; this.size = size; } @Override public String toString() { return "Block{" + "color='" + color + '\'' + ", size=" + size + '}'; } } class ColorSorter<B> implements Comparator<Block> { public int compare(Block o1, Block o2) { return o1.color.compareTo(o2.color); } } public class Test { public static void main (String[] args) throws InterruptedException { List<Block> blocks = new ArrayList<>(); blocks.add(new Block(10, "Green")); blocks.add(new Block(7, "Red")); blocks.add(new Block(12, "Blue")); Collections.sort(blocks, new ColorSorter()); System.out.println(blocks); } }

C is true. With Comparator you must override public int compare(Block b1, Block b2) method.

c is correct. Tested