下列程序的执行结果是______。 class A1 implements Runnable { public void run() { for(iht i = 0; i < 10; i++) { System.out.println('i =' + i); if(i == 3) break; } } } public class ex38 { public static void main(String[] args) { Thread th1 = new Thread(new A1()); th1.start (); } }