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Thread: looping through an ArrayList of objects with their own attributes

  1. #1
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    Question looping through an ArrayList of objects with their own attributes

    hello again,

    i am trying to loop through an ArrayList of type object. the objects have their own attributes and i'm trying to call a specific method that accesses a specific attribute. in this case, the objects refer to pets and i am trying to total up their leg count in separate java files. i'll have to call this method in my tester class.

    here is PetTester.java

    import java.util.ArrayList;
     
    /* This program tests the Pet superclass and its subclasses */
    public class PetTester
    {
     
    	public static void main(String [] args)
    	{	
    		Cat spider = new Cat("Spider", "Alley","Black", "crystals", 7);
    		Dog rover = new Dog("Rover", "Labrador","Chocolate", true, "large", 100);
    		Dog tippi = new Dog("Tippi", "Poodle","Silver",false, "small", 15);
    		Bird toucan = new Bird("Nismo", "toucan", 2, true);
     
    		ArrayList<Pet> pets = new ArrayList<Pet>();
    		pets.add(spider);
    		pets.add(rover);
    		pets.add(tippi);
    		pets.add(toucan);
     
    		String spiderName = spider.getName();
    		String spiderLitterType = spider.getLitterType();
    		String spiderColor = spider.getColor();
    		String spiderBreed = spider.getBreed();
    		int spiderLegs = spider.getLegs();
    		System.out.println(spiderName + " who is of type " + spiderBreed + " and color " + spiderColor +
    		" which uses " + spiderLitterType + " litter has " + " legs: "+ spiderLegs);
     
    		String roverName = rover.getName();
    		boolean roverTraining = rover.getTrained();
    		String roverSize = rover.getSize();
    		String roverColor = rover.getColor();
    		String roverBreed = rover.getBreed();
    		int roverLegs = rover.getLegs();
     
    		System.out.println(roverName + " who is of type " + roverBreed + " and color " + roverColor +
    		" and " + roverSize + " size which is trained " + roverTraining +
    		" has " + " legs: "+ roverLegs);
     
    		System.out.println(tippi.getName() + " who is of type " + tippi.getBreed() + " and color " + tippi.getColor() + " and " + tippi.getSize() +
    		" size which is trained " + tippi.getTrained() + " weighs " + tippi.getWeight() + " has " + " legs: "
    		+ tippi.getLegs());
     
    		System.out.println(toucan.getName() + " is a " + toucan.getBreed() + " who has " + toucan.getLegs()
    				+ " legs, and " + toucan.canTalk() + " talk.");
    	}
    }

    now here is Pet.java where this method, totalLegs(ArrayList<Pet> pets) is actually created.
    import java.util.ArrayList;
     
    public class Pet
    {
    	String name;
    	String breed;
    	String color;
    	int legs;
    	int weight;
    	boolean speaks;
     
    	public Pet(String name, String breed, String color, int legs, int weight)
    	{
    		this.name = name;
    		this.breed = breed;
    		this.color = color;
    		this.legs = legs;
    		this.weight = weight;
    	}
     
    	public Pet(String name, String breed, String color, int weight)
    	{
    			this.name = name;
    			this.breed = breed;
    			this.color = color;
    			this.legs = 4;
    			this.weight = weight;
    	}
     
    	public Pet(String name, String breed, int legs, boolean speaks)
    	{
    		this.name = name;
    		this.breed = breed;
    		this.legs = 2;
    		this.speaks = speaks;
    	}
     
    	public Pet()
    	{
    		this.name = "";
    		this.breed = "mutt";
    		this.color = "black";
    		this.legs = 4;
    		this.weight = 0;
    	}
    	public String getName()
    	{
    			return name;
    	}
     
    	public String getBreed()
    	{
    		return breed;
    	}
     
    	public String getColor()
    	{
    		return color;
    	}
     
    	public int getLegs()
    	{
    		return legs;
    	}
    	public int getWeight()
    	{
    		return weight;
    	}
     
    	[B]public static int totalLegs(ArrayList<Pet> pets)
    	{
    		int totalLegs = 0;
    		for (int i = 0; i < pets.size(); i++)
    		{
    			totalLegs = pets.getLegs();
    		}[/B]
    	}
    }

    how do i access their parameters and add them all up?


  2. #2
    Member wolfgar's Avatar
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    Default Re: looping through an ArrayList of objects with their own attributes

    thats easy , i do that all the time

    int legCount = 0;  // create the int to total the legs 
    for ( int i = 0; i < pets.size(); i++){
       legCount += pets.get(i).getLegs(); // use the get(i) to get that index of pet , and then the getLegs() 
    }                                                            // to return the number of legs that that pet has to be added to the total
    Programming: the art that fights back

  3. #3
    Member Darryl.Burke's Avatar
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    Default Re: looping through an ArrayList of objects with their own attributes

    Sure thing, but would a cat named spider have 4 or 8 legs?

    Or maybe none, what with a 100 lb (kg?) dog being so near

    db

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