How to increasing Array sizes , add a new Array slot at the end of the array?

Question

i am building a program like a Shop that have products and have the options of sell them with price and everything .. i wanted to make a options that will allow me to add new Products to the array from the program the its self for doing that i need to increase my array length . and i kind of stuck know , ty for all your help !!

Proudact MilkProd = new Proudact("Milk", 5.55, 50, 10, 0);
Proudact ChessProd = new Proudact("Chess", 4.35, 50, 10, 1);
Proudact AppleProd = new Proudact("Apple", 1.25, 50, 10, 2);
Proudact WotermelonProd = new Proudact("Wotermelon", 6.21, 50, 10, 3);

Proudact [] MyArray = {MilkProd,ChessProd,AppleProd,WotermelonProd};
NewProd(MyArray);

public static void NewProd(Proudact[] MyArray){
    Scanner scan = new Scanner(System.in);
    for (int i = 0; i < 1; i++) {
        MyArray[length] = MyArray[MyArray.length+1];
        System.out.println("Enter Proudact Name : ");
        String Name = scan.next();
        System.out.println("Enter Proudact Price : ");
        int price = scan.nextInt();
        System.out.println("Enter Proudact Stuck : ");
        int Stuck = scan.nextInt();
        System.out.println("Enter Proudact MinStuck");
        int minStuck = scan.nextInt();
        System.out.println("Enter Proudact Id :");
        int id = scan.nextInt();
        Proudact NewProudact = new Proudact(Name,price,Stuck,minStuck, id);
        MyArray[MyArray.length]=NewProudact;
    }
}

Possible duplicate of [java dynamic array sizes?](http://stackoverflow.com/questions/1647260/java-dynamic-array-sizes) — fabian, Oct 23 '15 at 10:29
Use an [`ArrayList`](http://docs.oracle.com/javase/8/docs/api/java/util/ArrayList.html) — khelwood, Oct 23 '15 at 10:30
Arrays have a fixed size, a static length. You cannot increase or decrease their size. You should use an `ArrayList` instead. Arrays are useful but are nothing compared to OOP solutions. — Luke Joshua Park, Oct 23 '15 at 10:30

score 3 · Answer 1 · answered Oct 23 '15 at 10:32

3

in Java, arrays can not be dynamically enlarged. I suggest you'll use ArrayList instead.

answered Oct 23 '15 at 10:32

Nir Levy

12,750
3
21
38

Kiki · Accepted Answer · 2015-10-23T10:39:14.310

Why don't you just use a list instead of array because Arrays have static lengths but lists have dynamic.

So instead of:

Proudact[] MyArray = ...

Create new list of type Proudact like this:

List<Proudact> myList = new ArrayList<Proudact>();

And then you can simply add items to list like this:

myList.add(new Proudact(Name,price,Stuck,minStuck, id));

So the full example for your case should look something like this:

List<Proudact> myList = new ArrayList<Proudact>();

myList.add(new Proudact("Milk", 5.55, 50, 10, 0));
myList.add(new Proudact("Chess", 4.35, 50, 10, 1));
myList.add(new Proudact("Apple", 1.25, 50, 10, 2));
myList.add(new Proudact("Wotermelon", 6.21, 50, 10, 3));

public static void NewProd(Proudact[] MyArray){
    Scanner scan = new Scanner(System.in);
    for (int i = 0; i < 1; i++) {
        System.out.println("Enter Proudact Name : ");
        String Name = scan.next();
        System.out.println("Enter Proudact Price : ");
        int price = scan.nextInt();
        System.out.println("Enter Proudact Stuck : ");
        int Stuck = scan.nextInt();
        System.out.println("Enter Proudact MinStuck");
        int minStuck = scan.nextInt();
        System.out.println("Enter Proudact Id :");
        int id = scan.nextInt();
        myList.add(new Proudact(Name,price,Stuck,minStuck, id));
    }
}

Check java collections tutorial here for more details.

score 0 · Answer 3 · answered Oct 23 '15 at 10:33

0

You are going to have to create a new array of larger size and copy all data from the old array over there. But must you use an array? A Set would be much easier to use

answered Oct 23 '15 at 10:33

Blorg Chacha

61
6

score 0 · Answer 4 · answered Oct 23 '15 at 10:37

Use an ArrayList and then convert it to array if that is what you want in the end.

List<Proudact> proudactList = new ArrayList<>();

populate it with objects of Proudact class & then convert it to array

Proudact[] array = proudactList.toArray(new Proudact[proudactList.size()]);

How to increasing Array sizes , add a new Array slot at the end of the array?

4 Answers4