in his book: Ivor Horton's Beginning Java 2 JDK 5 edition on page 227 he uses in a constructor the word final:

Point(final Point oldPoint) {
x=oldPoint.x
y=oldPoint.y
}

what does the keyword final does here? if you don't use it the results remain the same. Can someone give me an example where it does matter that you use the keyword final in the argument of a constructor?

thnx,

Greets,
Leville

Never used keyword "Final" when passing in as a parameter to a method, but an educated guess is that the parameter, in this case a value type, is immutable (can't be changed)

the Point you're passing in is a reference type, so within the function, you couldn't do something like:

oldPoint = new Point(10,20)

Because this would violate the final clause

Again, just an educated guess

thanks

I remember reading somewhere about using Final as an access modifier and agree with the above posting. It can also be used to prevent the overriding of methods in sub classes if the method in the superclass is defined as Final.

Hope this helps
Mark

hi

In three ways we use keyword final.
1) If any word declared as final means its value cant change.
2) If any method declared as final then the method we cant override in the base class.
3) If any class is declared as final then it cant participate in inheritence. It means we cant create base class using it.

i hope it will helps u,
ch.venki

yeah. It means that the value of the parameter can't be changed.So if you have some value which don't want to be changed. You'd better do it like this.

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