How can I make arrays with own objects in Java in Android Studio.

Question

I have a long piece of code that looks like this

Kwas a1 = new Kwas("Kwas Azotowy(V)", "HNO3");
// etc..
Kwas a17 = new Kwas("Kwas FluorkoWodorowy", "HF");

How can I write it as an Array? I tried something like

Kwas[] a = new Kwas[17]

But it didn`t work.

My "Kwas" class looks like the following:

public class Kwas {
String name;
String formula;

public Kwas( String nazwa, String wzor)
{
    name = nazwa;
    formula = wzor;
}

void setName(String c)
{
name = c;
}
void setFormula(String c)
{
    formula = c;
}
public String getName()
{
    return name;
}
public String  getFormula() {return formula;}

}

You said "it didn't work", but I am curious as to what error you encountered when you tried your code? — WoogieNoogie
– WoogieNoogie, Commented Oct 9, 2017 at 14:27
Nouman Ch " It cannot find symbol class Kwas " but when i make it not in array everything works. — Jakub Lelek
– Jakub Lelek, Commented Oct 9, 2017 at 14:33
is your Kwas class in the same package? if not are you importing it to your current class? — Procrastinator
– Procrastinator, Commented Oct 9, 2017 at 14:52

Mykhailo Voloshyn · Accepted Answer · 2017-10-09 14:29:04Z

6

You can do this:

List<Kwas> list = new ArrayList<Kwas>();
list.add(a2);

answered Oct 9, 2017 at 14:29

Mykhailo Voloshyn

6043 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Berkay Tutal Over a year ago

Also you can try list.add(new Kwas("Kwas Siarkowodorowy", "H2S"));

Jakub Lelek Over a year ago

list.add(a2); In error i have got there "<identifier> expected"

Mykhailo Voloshyn Over a year ago

Make sure that you have import java.util.ArrayList; import java.util.List;

Mykhailo Voloshyn · Accepted Answer · 2017-10-09 14:46:50Z

3

Just implement an ArrayList like this:

ArrayList<Kwas> newArray= new ArrayList<>();

And then:

newArray.add(a2);
newArray.add(a3);
newArray.add(a4);
newArray.add(a5);
newArray.add(a6);
newArray.add(a7);  
...
...

Then if you want to get an specific item just write something like this:

newArray.get(1).getName(); //for example

edited Oct 9, 2017 at 14:46

Mykhailo Voloshyn

6043 silver badges11 bronze badges

answered Oct 9, 2017 at 14:33

Faustino Gagneten

2,7842 gold badges31 silver badges56 bronze badges

3 Comments

Jakub Lelek Over a year ago

But in android studio it cannot find symbol add.

Faustino Gagneten Over a year ago

Make sure that the array is type of ArrayList.

Faustino Gagneten Over a year ago

@JakubLelek just accept this answer it solved your problem. Thanks

MrZarq · Accepted Answer · 2017-10-09 14:53:54Z

1

I can't comment yet, so I have to provide it as an answer. Everyone is answering here how OP can construct a List, but no one is actually answering how he can create an array, which is probably very confusing for OP who might now think you can't create arrays of self-defined objects. You definitely can. But I don't know what the problem is.

Kwas[] a1 = new Kwas[17];

is definitely the right syntax. Are you sure you include the class? Can you post the exact code and error?

My guess is that you didn't import your class. In Android Studio, try placing your cursor after Kwas and pressing Ctrl+Space. This should show a dropdown list. Select the first line and press enter. Now it should have added an import to your class.

edited Oct 9, 2017 at 14:53

answered Oct 9, 2017 at 14:46

MrZarq

2583 silver badges13 bronze badges

2 Comments

Moshe Edri Over a year ago

The question is about android studio not plain java, android studio don´t support that kind of array

MrZarq Over a year ago

I don't know what you're talking about. Android Studio absolutely supports arrays of objects.

JasperHsu · Accepted Answer · 2017-10-09 16:32:22Z

1

ArrayList<yourObjectName> arrayName = new ArrayList<yourObjectName>();

Then .add(object) on every object

edited Oct 9, 2017 at 16:32

JasperHsu

4511 bronze badges

answered Oct 9, 2017 at 14:31

Moshe Edri

2442 silver badges10 bronze badges

Comments

JasperHsu · Accepted Answer · 2017-10-09 15:00:15Z

0

You can simply type:

ArrayList<ObjectType> arrayName = new ArrayList<ObjectType>();

Adding Elements:

arrayName.add(someObject);

Removing Elements:

arrayName.remove(arrayName.get(someInteger));

Getting Elements:

arrayName.get(someInteger);

PS: Don't forget to import:

import java.util.ArrayList;

answered Oct 9, 2017 at 15:00

JasperHsu

4511 bronze badges

Collectives™ on Stack Overflow

How can I make arrays with own objects in Java in Android Studio.

5 Answers 5

3 Comments

3 Comments

2 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

3 Comments

3 Comments

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related