Java Interview Question
Java
Interview
Questions:
Difference
between final finally and finalize()
Final :
final is modifier is
applicable for classes methods and the variables.
à If we declared variable as final then it will become constants.
à if we declared
method as final. In child class we can’t override this method.
à if we declared class as final then we can’t extends(inherited) this class.
//If we declared variable
as final then it will become constants.
public class ClassFinal {
public static void main(String[] args) {
final int a = 5;
a = 4; // we can't reassign variable
value , becaz this variable is final....
}
}
OUTPUT: error
//if we declared method as
final. In child class we can’t override this method.
class parent
{
public final void m1()
{
System.out.println("parent");
}
}
class child extends parent
{
public void m1()
{
System.out.println("child");
}
}
public class ClassFinal {
public static void main(String[] args) {
child c = new child();
c.m1();
}
}
OUTPUT: Error…
//if we declared class as final then we can’t extends(inherited)
this class.
final class parent
{
public
void m1()
{
System.out.println("parent");
}
}
class child extends parent
{
public void m1()
{
System.out.println("child");
}
}
public class ClassFinal {
public static void main(String[] args) {
child c = new child();
c.m1();
}
}
OUTPUT: Error ..
Finally:
finally is a block always associated with try – catch block
To maintain clean up code.
try
{
// risky code
}
catch( Exception e)
{
// handle the exception in try block
}
Finally
{
// clean up code
// close the file…like that..
}
Finalize():
Finalize() is the method
which is always called by garbage
collector just before destroying an object
To perform clean up
activities.
NOTE: finally meant for
cleanup activities related to try block.
Where as finalize() meant
for cleanup activities related to the object.
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