Final Arguments ..

[karimkhan pathan]

Can final arguments of a method can changed ??

[Dawn Charangat]

final arguments in any scope cannot be changed. They can be read from, any number of times.

[karimkhan pathan]

thanks Dawn

[Christophe Verré]

Their content can be changed though.

[Campbell Ritchie]

Please explain more about changing content, Christophe.

[Muhammad Khojaye]

karimkhan pathan wrote:Can final arguments of a method can changed ??

Values cannot be modified after initialization. however, they are stored as values. Just to confuse things static final variables in Java are compiled as in-line constants. In other words, if you change a static final value, you need to recompile everything that uses it or they will continue using the old value. That catches out every Java newbie sooner or later.

[Christophe Verré]

Please explain more about changing content, Christophe.

package divers;

class Dog {
	private String name;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}


public class FinalParam {

	public static void callDog(final Dog dog) {
		// setting a parameter to final doesn't mean that you cannot change its content
		dog.setName("Bill");
	}
	
	public static void main(String[] args) {
		Dog myDog = new Dog();
		myDog.setName("Joe");
		callDog(myDog);
		System.out.println("My dog's name is " + myDog.getName());
	}
}

[karimkhan pathan]

But when a primitive is used as a argument for the method .
we cannot change the value !!
when we use a object ref how we can change the contents of the object?

[Amy Crowley]

Final variables cannot be reassigned new values once they've been initialized. For object reference variables, this means that the final variable cannot be re-assigned to a different object. The object itself may be changed, however -- the certification tutorial i've been reading (SCJP 6 Study Guide, Sierra & Bates) put it this way:

There are no final objects, only final references.

[Campbell Ritchie]

karimkhan pathan wrote:when we use a object ref how we can change the contents of the object?

That is what I expected, and why I sugested Christophe give us more details (thank you).

You cannot change which object it is, but the methods allow you to change the "state" of the object; its fields can be altered.

[karimkhan pathan]

Thanks campbell...It was really helpful ...

[Campbell Ritchie]

You're welcome (on behalf of everybody who replied)