主线程先执行还是自己创建的线程先执行，或者优先级是一样的？

public class Dog implements Runnable {

	@Override
	public void run() {
		for(int i=1;i<=3;i++) {
			System.out.println(Thread.currentThread().getName()+"A,Cat"+i);
		}

	}

}

public class Cat implements Runnable {

@Override

public void run() {

for (int i = 1; i <= 3; i++) {

System.out.println(Thread.currentThread().getName() + "A,Dog" + i);

}

}

}

public class Test {

public static void main(String[] arg) {

Runnable cat = new Cat();

Runnable dog = new Dog();

for (int i = 1; i <= 3; i++) {

System.out.println(Thread.currentThread().getName() + "  main thread" + i);

}

Thread thc = new Thread(cat);

Thread thd = new Thread(dog);

thc.start();

thd.start();

char[] c = new char[26];

for (int i = 0; i < 26; i++) {

c[i] = (char) (i + 97);

System.out.println(c[i]);

}

}

}