ArrayList method help?

[Goonrider72]

Hi there
great sight iv been reading and learning from alot of the questions here.
iv just started programming using java... we use Bluej at uni.
my problem is as follows:
i have 2 classes. the 1st class is called soldiers and creates objects called soldiers and stores their attributes, eg name, id number, rank etc...
The second class is taskForce which stores which has an add method and adds soldiers to the task force by storing them in an arrayList
the method i need to create now is a list method but the list method must only list those soldiers which share the same attribute, eg rank
The only way i know how to list some thing is:
public void listSoldiers()
{
System.out.println(toString());
}

im presuming something like:
public void ListByRank(String sRank)
{

for(Soldier soldier : taskForce)
{

System.out.println(toString());

}
}

not sure on the rest if some one could point me in the right direction it would be a great help.

[r035198x]

Hi there
great sight iv been reading and learning from alot of the questions here.
iv just started programming using java... we use Bluej at uni.
my problem is as follows:
i have 2 classes. the 1st class is called soldiers and creates objects called soldiers and stores their attributes, eg name, id number, rank etc...
The second class is taskForce which stores which has an add method and adds soldiers to the task force by storing them in an arrayList
the method i need to create now is a list method but the list method must only list those soldiers which share the same attribute, eg rank
The only way i know how to list some thing is:
public void listSoldiers()
{
System.out.println(toString());
}

im presuming something like:
public void ListByRank(String sRank)
{

for(Soldier soldier : taskForce)
{

System.out.println(toString());

}
}

not sure on the rest if some one could point me in the right direction it would be a great help.

Let's see your Soilder class.
And please use code tags when posting code.

[JosAH]

I assume that you have a list that contains all types of Soldiers:

List<Soldier> Soldiers= new ArrayList<Soldier>();
 

I also assume that you want to iterate over that list and if a Soldier fits a certain
filter it is printed, otherwise it is ignored:

void list(Filter filter) {
   for (Soldier soldier : Soldiers)
      if (filter.fit(soldier))
         System.out.println(soldier);
}
 

So, also assuming a Filter interface exists like this:

public interface Filter {
   public boolean fit(Soldier soldier);
}
 

All you have to do now is implement a few simple classes that implement the
Filter interface and you're in business. Note that I implemented the rest of the
code assuming nothing about the other classes, i.e. even a Soldier can be an
interface as the Filter is an interface. It's a general design rule: "code to the
interface, not the implementation (class)". It makes your life easier and your
code more flexible.

kind regards,

Jos