Bounded Array

[bugger]

We can declare an ArrayList bounded by String as shown below:

Code:

ArrayList<String> arrayList = new ArrayList<String>();

Can we also declare a simple array bounded by String or some other datatype? Please write syntax.

Thanks in advance.

[tim]

Hello bugger.

I think it's just the normal declaration of an array of type String:

Code:

int size = 10;
String[] array = new String[size];

or in Synax:

Code:

int size = 10;
<type here>[] array = new <type here>[size];

Hope this helps.

[roots]

If you are concerned on including the Generics things as well, make it like

Code:

int size = 10 ;
ArrayList<Object> array = new ArrayList<Object>[size] ;

If your elements in array are not of same type then you need to cast them to their original type before using them. instanceof operator can be useful in this case.

[gibsonrocker800]

Whenever i want to have a group of objects of a type other than String or ints or doubles, i use ArrayList. It's better in the sense that it doesn't have a fixed length. When you have an array there can only be a certain number of objects in that array, but in an ArrayList you can add as many as you'd like.

I also like using HashSet when order doesn't matter, and when you want it to not repeat elements. A while ago i started on my first real test of my logic skills: a Sudoku game, and, my knowledge didn't really offer a solution to how i could check if the user won. But, when i learned about HashSets it completely solved my problem. Basically what i did was, add all the numbers (of a row, column, or square) the user entered into the HashSet, and if the size of the HashSet is less than 9, they didn't win (there's a method to check the rows, colums, and squares). The reason for this is, if there are not 9 number in the HashSet, that means that the user repeated a number (and HashSets silently ignore when a duplicate element is an argument of the add method), which means the user didn't win the game.

So yeah i mean i guess everyone has their own style. Different people like using different classes that do virtually the same thing. Its just a matter of preference.

[bugger]

Thanks all of you. It was a simple thing that I was not thinking of:

Code:

int size = 10;
String[] array = new String[size];

But I learnt that if size is not defined, we can use ArrayList. And also generics can be used.

Again, thanks guys.