Why null null?

[Sandeep Sachan]

Hi, I got this question in to my MasterExam i am not getting why the answer is Null and null

  
 
class Mineral{}
class Gem extends Mineral{}
class Miner
{
static int x=7;
static String s=null;
public static void getWeight(Mineral m)
{
int y=0/x;
System.out.print(s+" ");
}
public static void main(String [] args)
{
Mineral [] ma = {new Mineral(), new Gem()};
for(Object o : ma)
getWeight((Mineral)o);
}
}
  

[Christophe Verré]

s is always null. What do you expect it to be ?

[Sandeep Sachan]

I am bit confused into this perticular code

    
public static void main(String [] args)
{
Mineral [] ma = {new Mineral(), new Gem()};
for(Object o : ma)
getWeight((Mineral)o);
}

please elaborate it in little deep, i ma not getting the part which is there in to main method.

[Christophe Verré]

// Declare an array of Mineral
// Make two Mineral (a Mineral and a Gem), and put them in the array
Mineral [] ma = {new Mineral(), new Gem()};
 
// Loop the Mineral one by one, from array "ma". Set each item retrieved in "o"
for(Object o : ma) {
// o contains the Mineral which is in the array. Output its weight
getWeight((Mineral)o);
}

[dhwani mathur]

ok!!
public static void main(String [] args)
{
Mineral [] ma = {new Mineral(), new Gem()};

for(Object o : ma)
getWeight((Mineral)o);
}

here Mineral is the Base class,ma is the reference to the class Mineral
you will notice at right side new Mineral,new Gem......now here it is instantiated by writing "new" ...."so ma becomes the object".

Later enhanced for loop is used,where Object o is assigned object ma(actualy value),than getweight method is called.

i hope it helps you to atleast some extent.

[Bharat Makwana]

Originally posted by Sandeep Sachan:
[QB]Hi, I got this question in to my MasterExam i am not getting why the answer is Null and null

Sorry budy,but answer is null null , you have capitalized N in first one

[Sandeep Sachan]

Thanks ranchars,

[prateek urmaliya]

ma is the reference to the class Mineral

    
// Declare an array of Mineral
// Make two Mineral (a Mineral and a Gem),
// and put them in the arrayMineral 
Mineral [] ma = {new Mineral(), new Gem()};

[ June 25, 2007: Message edited by: prateek urmaliya ]