Implication of autoboxing

[Rahul Kumar]

Hi ,
Can anybody explain me here in the code the implication of autoboxing...

public class Ex {

Integer i;
int j;

public void go(){
//i=j;
j=i;
System.out.println("value of j :"+ j);
System.out.println("value of i :"+ i);
}

public static void main(String[] args) {
Ex obj=new StaticEx();
obj.go();

}

}

Regards,
Amazer

[Gowher Naik]

[code]
public class Ex {

Integer i=0;
int j;

public void go(){
j=i; //line 7
System.out.println("value of j :"+ j);
System.out.println("value of i :"+ i);
}

public static void main(String[] args) {
Ex obj=new Ex();
obj.go();

}

}
/[code]
in code above i set Integer i=0;
then unboxing will occur at line 7.
in your code Integer i is null so there is NullpointException.
Boxing will occur when Integer i will refer to some Object.
But in your code Integer i donot refer to any object so boxing will not occur.

[Gowher Naik]

public class Ex {
 
Integer i=0;
int j;
 
public void go(){
j=i;          //line 7
System.out.println("value of j :"+ j);
System.out.println("value of i :"+ i);
}
 
public static void main(String[] args) {
Ex obj=new Ex();
obj.go();

}
 
}

in code above i set Integer i=0;
then unboxing will occur at line 7.
in your code Integer i is null so there is NullpointException.
Boxing will occur when Integer i will refer to some Object.
But in your code Integer i donot refer to any object so boxing will not occur.