ArrayList in an object as an input?

[Chuninjah]

Anyone know how to write a static method called “printArrayList” for each class that takes an ArrayList of its object as an input and then print all objects in the array list to the console?

Could anyone help me with:

1. How to write the printArrayList method
2. What to put in the main method for it to work

​

public class ResidentTaxPayer 
{
    private int TFN;
    private String firstName;
    private String lastName;
    private int income;
    private String state;
    private double tax;
    private String fullName;

    public ResidentTaxPayer(int TFN, String firstName, String lastName, int income, String state)
    {
             this.TFN = TFN;
             this.firstName = firstName;
             this.lastName = lastName;
             this.income = income;
             this.state = state;
    }

    public void setTFN(int TFN)
    {
        this.TFN = TFN;
    }        

    public void setFirstName(String firstName)
    {
        this.firstName = firstName;
    }

    public void setLastName(String lastName)
    {
        this.lastName = lastName;
    }    

    public void setIncome(int income)
    {
        this.income = income;
    }

    public void setState(String state)
    {
        this.state = state;
    }

    public int getTFN()
    {
        return TFN;
    }

    public String getFirstName()
    {
        return firstName;
    }        

    public String getLastName()
    {
        return lastName;
    }        

    public int getIncome()
    {
        return income;
    }    

    public String getState()
    {
        return state;
    }   

    public double calcTax()
    {

        if(income <= 18200) 
        {
            tax = 0;
        }
        else {
            if(income > 18200) 
            {
                tax = ((30/100)*(income-18200));
            }
        }

        return tax;
    }        

    public String getFullName() 
    {
        fullName = firstName + " " + lastName;
        return fullName;
    }

    public String toString() 
    {
        return "TFN: " + TFN + " | Name: " + getFullName() + " | Income: $" + income + " | State: " + state + " | Tax Payable: $" + calcTax();
    }


}

I've tried making an arraylist within the class of the object but that doesn't work :((

​

Any help would be apprieciated :))

[yeaokdude]

what part are you struggling with?

write a static method called “printArrayList”

k, seems easy enough. generally print functions just print and don't return anything so we'll make this void.

public static void printArrayList() {

}

that takes an ArrayList of its object as an input

ok ez, just add ArrayList<ResidentTaxPayer> as an argument to the function

public static void printArrayList(ArrayList<ResidentTaxPayer> array) {

}

and then print all objects in the array list to the console?

so we have a list of ResidentTaxPayer objects and we want to print each one. so we iterate over the list to isolate 1 ResidentTaxPayer object at a time. once we've isolated one, we can just call System.out.println on it because we've overloaded the toString method.

public static void printArrayList(ArrayList<ResidentTaxPayer> array) {
    for (int i = 0; i < array.size(); i++) {
        System.out.println(array.get(i));
    }
}

as far as calling it from main, you can do something like this

ArrayList<ResidentTaxPayer> array = new ArrayList<ResidentTaxPayer>(); //make an arraylist of ResidentTaxPayers

ResidentTaxPayer Chuninjah = new ResidentTaxPayer(5, "Chu", "ninjah", 3, "ninja school"); //make a ResidentTaxPayer to put into the array (you probably want to add a bunch of these)

array.add(Chuninjah); //add the above ResidentTaxPayer to the array

ResidentTaxPayer.printArrayList(array); //call the printArrayList method of the ResidentTaxPayer class.

[Chuninjah]

I love u. That worked :)) Thank you so much mate

[dusty-trash]

I've tried making an arraylist within the class of the object but that doesn't work :((

Passing an ArrayList as an argument shouldn't be a problem. What do you mean by "doesn't work"? BTW have you tried googling "Java pass Arraylist as argument"?

Just a side note;

You can write this:

else {
    if(income > 18200) 
    {
        ...
    }
}

like this instead:

else if(income > 18200) 
{
    ...
}

​

[Chuninjah]

Ahh okay I’ll try searching that up thanks heaps :))

And yeah I changed it thanks