StringBuilder sb = new StringBuilder("a");
String s = sb.toString();
sb.append("b");
System.out.println(s);

char c = 'A';
c += 2;
System.out.println(c);

int s = 0;
for (int i = 1; i <= 4; i++) {
  if (i % 2 == 1) continue;
  s += i;
}
System.out.println(s);

int[] arr = new int[3];
System.out.println(arr[1]);

static int sum(int... xs){ int s=0; for(int x: xs) s+=x; return s; }
System.out.println(sum(1,2,3));

String a = "hi";
String b = new String("hi").intern();
System.out.println(a == b);

int[] a = new int[4];
java.util.Arrays.fill(a, 2);
System.out.println(a[3]);

void bump(Integer x){ x++; }
Integer v = 1;
bump(v);
System.out.println(v);

int[] a = {1,2,3};
int[] b = java.util.Arrays.stream(a).map(x -> x * 2).toArray();
System.out.println(a[1] + "," + b[1]);

class A { static { System.out.print("A"); } }
class B extends A { static { System.out.print("B"); } }
new B();