Java Initialize an int array in a constructor

Question

I have a class and in that class I have this:

 //some code  private int[] data = new int[3];  //some code 

Then in my constructor:

public Date(){     data[0] = 0;     data[1] = 0;     data[2] = 0; } 

If I do this, everything is OK. Default data values are initialized but if I instead do this:

public Date(){     int[] data = {0,0,0}; } 

It says:

Local variable hides a field 

Why?

What's the best way to initialize an array inside the constructor?

Answer 1

private int[] data = new int[3]; 

This already initializes your array elements to 0. You don't need to repeat that again in the constructor.

In your constructor it should be:

data = new int[]{0, 0, 0}; 

Answer 2

You could either do:

public class Data {     private int[] data;      public Data() {         data = new int[]{0, 0, 0};     } } 

Which initializes data in the constructor, or:

public class Data {     private int[] data = new int[]{0, 0, 0};      public Data() {         // data already initialised     } } 

Which initializes data before the code in the constructor is executed.