Create list with different objects

Question

I have a method that takes in a List<> and adds all the numbers in the list together and returns if the number is = 100

My problem is that I want to use the same method for a number of different types of lists

So instead of having this

public boolean checkPercent(List<BarStaff> associates){..same..}
public boolean checkPercent(List<Waiters> associates){..same..}
public boolean checkPercent(List<KitchenStaff> associates){..same..}

I want to have this

public boolean checkPercent(List<could be any type> associates){..same..}

Instead of reusing the same code just of different lists, is there a way to use the same code for all the different types of lists (the staff have the same values in them so they are not different in any way)?

score 8 · Accepted Answer · answered Jul 17 '12 at 15:20

8

You could use a parameterized method:

public <T> boolean checkPercent(List<T> associates)
{
    // snip...
}

or just accept any list:

public boolean checkPercent(List<?> associates)
{
    // snip...
}

answered Jul 17 '12 at 15:20

Matt Ball

354,903
100
647
710

score 7 · Answer 2 · answered Jul 17 '12 at 15:20

7

You may create a generic method:

public <T> boolean checkPercent(List<T> associates) {
    ... your code ...
}

answered Jul 17 '12 at 15:20

Howard

38,639
9
64
83

score 3 · Answer 3 · answered Jul 17 '12 at 15:21

3

Use generics:

public <T> boolean checkPercent(List<T> associates){...}

answered Jul 17 '12 at 15:21

Eng.Fouad

115,165
71
313
417

Hans Z · Answer 4 · 2012-07-17T15:36:04.267

2

The object-oriented approach would be to have BarStaff, Waiters, and KitchenStaff implement a Employee interface that has a method public int getPercentage().

public boolean checkPercent(List<? extends Employee> associates)
{
    foreach (Employee associate in associates)
    {
        int i = associate.getPercentage();
        // rest of code.
    }
}

edited Jul 17 '12 at 15:36

answered Jul 17 '12 at 15:24

Hans Z

4,664
2
27
50

I don't think this would work. See http://stackoverflow.com/questions/9810445/listmapstring-string-vs-list-extends-mapstring-string – Eng.Fouad Jul 17 '12 at 15:25
Extends and implements are different. – Hans Z Jul 17 '12 at 15:26
2

This could work if it was an array, i.e `Employee[]` will accept `BarStaff[]`. However, I think the right way to do is `List extends Employee>`. – Eng.Fouad Jul 17 '12 at 15:28

Create list with different objects

4 Answers4