1)
class Mammal{
String name="furry";
String makeNoise(){ return "generic noise";}
}
class Zebra extends Mammal{
Sring name="stripes";
String makeNoise(){return "bray";}
}
public class ZooKeeper{
public static void main(String [] args){ new ZooKeeper().go();}
void go(){
Mammal m = new Zebra();
System.out.println(m.name + m.makeNoise());
}
}
What is the Result ?
2)SCJP:
public class Dark{
int x =3;
public static void main(String[] args){
new Dark().go1();
}
void go1(){
int x;
go2(++x);
}
void go2(int y ){
int x = ++y;
System.out.println(x);
}
}
What is the Result ?
3)
import java.io.*;
class Player {
Player() { System.out.print("p"); }
}
class CardPlayer extends Player implements Serializable {
CardPlayer() { System.out.print("c"); }
public static void main(String[] args) {
CardPlayer c1 = new CardPlayer();
try {
FileOutputStream fos = new FileOutputStream("play.txt");
ObjectOutputStream os = new ObjectOutputStream(fos);
os.writeObject(c1);
os.close();
FileInputStream fis = new FileInputStream("play.txt");
ObjectInputStream is = new ObjectInputStream(fis);
CardPlayer c2 = (CardPlayer) is.readObject();
is.close();
} catch (Exception x ) { }
}
}
4)
import java.io.*;
class Keyboard { }
public class Computer implements Serializable {
private Keyboard k = new Keyboard();
public static void main(String[] args) {
Computer c = new Computer();
c.storeIt(c);
}
void storeIt(Computer c) {
try {
ObjectOutputStream os = new ObjectOutputStream(
new FileOutputStream("myFile"));
os.writeObject(c);
os.close();
System.out.println("done");
} catch (Exception x) {System.out.println("exc"); }
}
}
5)
What is output ?
class Cat { }
class Dog {
public static void main(String [] args) {
Dog d = new Dog();
System.out.println(d instanceof Cat);
}
}
6)
class Boxing2 {
static Integer x;
public static void main(String [] args) {
doStuff(x);
}
static void doStuff(int z) {
int z2 = 5;
System.out.println(z2 + z);
} }
7)
package javaimp;
class Ouch {
static int ouch = 7;
public static void main(String[] args) {
new Ouch().go(ouch);
System.out.print(" " + ouch);
}
void go(int ouch) {
ouch++;
for(int ouch = 3; ouch < 6; ouch++)
;
System.out.print(" " + ouch);
}
}
What is the result?
-
5 7
-
5 8
-
8 7
-
8 8
-
Compilation fails
8)
class MyOuter2{
private String x = "Outer2";
void doStuff(){
String z = " local variable";
class MyInner{
public void seeOuter(){
System.out.println("Outer x is "+x);
System.out.println("Local var z is "+z);
}
}
}
}
What is the result ?
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