CODEWITHSUNDEEP
java
kumar
kumar

Reputation: 65

How can we create our own data type in java?

I have a requirement where I have to create my own data type and i should assign some bytes to the data types.
Example:

Datatype A : should have 1 byte of memory
Datatype B : should have 2 bytes of memory
Datatype C : should have 7 bytes of memeory etc..

Is there any way we can define our own data types and allocate some memory to them ?

Upvotes: 0

Views: 7597

Answers (4)

GhostCat
GhostCat

Reputation: 140457

There are a few "options" in Java to express types, namely: interfaces, classes, and enums.

In that sense, the best match would be a class, like:

public class TwoByteHolder {
  public final byte[] data = new byte[2];
}

An object of that class allows you to exactly store 2 bytes; the next "level" could be something like:

public class ByteHolder {
  public final byte[] data;

  public ByteHolder(int numberOfBytes) {
    data = new byte[ numberOfBytes ];
  }
  ...

But of course: the memory overhead would be enormous - Java isn't the the best language to deal with such requirements.

Upvotes: 3

bolec_kolec
bolec_kolec

Reputation: 510

You can create a new class which has specific fields. If you need exact size of fields you can use byte arrays.

class Data {

  public byte[] dataA = new byte[1];
  public byte[] dataB = new byte[2];
  public byte[] dataC = new byte[7];
  ...
}

Upvotes: 1

T.J. Crowder
T.J. Crowder

Reputation: 1074355

The only user-defined types available in Java are classes (including enums), and you cannot directly control how large they are. A class instance has many bytes of overhead you can't avoid having.

Upvotes: 1

Max
Max

Reputation: 985

You can't create data types in java, but you can create object classes, like this:

Class A {
    public byte[] bytes; 
}

Upvotes: 0

Related Questions