Java Puzzle

อ่านเจอในเอกสาร presentation ใน javaone 2005
ก็เลยลอกมาให้ดู

public class AnimalFarm{ 
    public static void main(String[] args) { 
        final String pig = "length: 10"; 
        final String dog = "length: " + pig.length(); 
        System.out.println("Animalsare equal: " + pig == dog); 
    } 
}

public class Assignment { 
    public static void main(String[] a) throws Exception { 
        int tricky = 0; 
        for (int i = 0; i < 3; i++) 
            tricky += tricky++; 
        System.out.println(tricky); 
    } 
} 

public class Loop {
    public static void main(String[] args) {
        int[][] tests = { { 6, 5, 4, 3, 2, 1 }, { 1, 2 }, { 1, 2, 3 },
                { 1, 2, 3, 4 }, { 1 } };
        int successCount = 0;
        try {
            int i = 0;
            while (true) {
                if (thirdElementIsThree(tests[i++]))
                    successCount++;
            }
        } catch (ArrayIndexOutOfBoundsException e) {
        }
        System.out.println(successCount);
    }

    private static boolean thirdElementIsThree(int[] a) {
        return a.length >= 3 & a[2] == 3;
    }
}

public class Mod {
    public static void main(String[] args) {
        final int MODULUS = 3;
        int[] histogram = new int[MODULUS];
        int i = Integer.MIN_VALUE;
        // This loop iterates over all intvalues
        do {
            histogram[Math.abs(i) % MODULUS]++;
        } while (i++ != Integer.MAX_VALUE);
        for (int j = 0; j < MODULUS; j++)
            System.out.print(histogram[j] + " ");
    }
}

อันสุดท้ายนี่งงอยู่ตั้งนาน สุดท้ายเปิด javadoc ดูแล้วค่อยร้อง อ๋อ