一道Java基础:继承的面试题

package com.me;

public class TestClassA
{
    public void printl()
    {
        int a = 3;
        System.out.println( "A:" + a );
    }

}

package com.me;

public class TestClassB
    extends TestClassA
{

    public void printl()
    {
        int b = 5;
        System.out.println( "B:" + b );
    }

    public static void main( String[] args )
    {
        TestClassA hehe = new TestClassB();
        hehe.printl();
    }

}

值是多少？
答案是：B:5