Searching arrays?

[mohaakilla51]

Is there a better way to do this:

// attackable[] is a array of Country objects. it is variable in length
    public boolean canAttack(Country c) 
    {
        int x;
        for(x = 0; (attackable[x] != c)&&(x < attackable.length); x++){};
        if((x < attackable.length) && (attackable[x] == c)) 
        {
            if(c.getOwner() == owner)
                return false;
            else
                return true;
        } else
            return false;
    }
 

That's a method that I'm working on for my compsci class... anyone know a more efficient way to do that? mainly just the

        int x;
        for(x = 0; (attackable[x] != c)&&(x < attackable.length); x++){};
        if((x < attackable.length) && (attackable[x] == c)) 
 

part, but any help or pointers with the rest would be appreciated too.

[Nepomuk]

There is a better way to do it indeed. For example, you don't have to have that for loop run without doing anything. And see, it tests the same thing as the if command beneath.

Then, you check

if(c.getOwner() == owner) // shouldn't that be done with equals? (see below)

and then return the opposite of that answer - that can be shortened a lot. Just have a look at this:

public boolean not(boolean myBoolean) {
    return !myBoolean;
}

It will always return the opposite of the boolean you gave - do you understand why?

Also, remember that as soon as you return a value, the rest of the code will not be run. So you can leave out some tests.

Now, isn't Country a own class? If so, you should compare it with

if(attackable[x].equals(c)) {...

Similar with the owner - if that's anything but a primitive data type, you should compare that with equals too.

Greetings,
Nepomuk

[mohaakilla51]

Lol, thanks :) I wrote that at like, midnight :P

Question, do I have to write my own equals method, or does java do that automatically for me?

[Nepomuk]

Lol, thanks :) I wrote that at like, midnight :P

Question, do I have to write my own equals method, or does java do that automatically for me?

You should write your own - this article should help you do so.

Greetings,
Nepomuk