橘园美术馆门票:java程序 问题解答

1、以下程序运行之后，程序输出的结果是?
char ch = 'b';

switch (ch) {
case 'a':
System.out.print(ch);
case 'b':
System.out.print(ch);
case 'c':
System.out.print(ch);
case 'd':
System.out.print(ch);
}

2、以下程序运行之后，三条输出的代码分别输出的结果是?
public class Foo {
int i;
static int s;
public static void main(String[] args) {
Foo f1 = new Foo();
System.out.println("f1.i is " + f1.i + " f1.s is " + f1.s);
Foo f2 = new Foo();
System.out.println("f2.i is " + f2.i + " f2.s is " + f2.s);
Foo f3 = new Foo();
System.out.println("f3.i is " + f3.i + " f3.s is " + f3.s);
}
public Foo() {
i++;
s++;
}
}

3、以下程序运行之后，程序的输出结果是？
public class Test {
public static void main(String[] args) {
String s1 = new String("Java");
String s2 = new String("Java");
System.out.print((s1 == s2) + " " + (s1.equals(s2)));
}
}

4、以下程序运行之后，程序输出的结果是?
public class A extends B {
int x = 1;
public static void main(String[] args) {
System.out.print(new A().x);
System.out.print(new B().x);
}
}
class B {
int x = 5;
}