display prime numbers that are also square numbers
while (i <= 100) {
j = 2;
while (j <= (int) Math.sqrt(i)) {
if (i % j == 0) break;
// else
j++;
}
if (j > (int) Math.sqrt(i)) {
// i is prime
if (Math.sqrt(i) % 1 == 0) {
// i is square
System.out.println(i);
}
}
i++;
}