Final keyword in Java

[Level8]

Hi, I want some example code and basic explanation of final keyword in JAVA. Can anyone provide me this? I am trying to improve my knowledge in java and want to learn new things. I am not having more knowledge about java. So, please give me details of final keyword.

[Praetor]

Hi, Final keyword is used in java for the purpose of making some housekeeping task. There may be possibility that your try catch block is not get executed but your final block gets executed at every time when your program would get executed. Therefore this block is used for making those executions which have to be done before moving out of the program. As whether your program gets exception or not, it has to execute the final block. That is why many times final block is used to close the connections, so no single connection is remain open to slow down the traffic of the two nodes.

[Katty]

Hi, you have not explained where did you want to use the final keyword. If a method is declared final then subclasses would be prevented from overriding or hiding it. It will give compile-time error. You can't declare them abstract.

It can be used as follows:

final class one 
{
int a, b;
void change (int x, int y) { a += x; b += y; }
}
class check
{
public static void main(String[] args) 
{
test[] p = new test[100];
for (int i = 0; i < p.length; i++) 
{
p[i] = new test();
p[i].change(i, p.length-1-i);
}
}
}

[kelfro]

Hi, you want to know about keyword final in java, right? In java basically, final simply means that the value will not going to change further.

Advantages:

• It is used only when you know that the value is not going to be changed further.
• It wont allow anyone to change that value further in anyway.
• It helps the compiler to generate code faster.

For example:
// final is used to ensure a variable is always assigned a value,
// and once assigned value never change.

final int a;
if ( x> 0 )
   {
   a=14;
   }
else if ( x < 0 )
   {
   a = 0;
   }
else
   {
  a = 7;
   }

[marcoterz]

You can find more information on all different uses of final here https://sites.google.com/site/javadvanced/final-keyword