What is the default value of an array in Java?

In Java, when an array is declared and initialized, each element of the array gets assigned a default value based on its type. The default values are stored in memory until they are explicitly assigned another value by the programmer. The default value depends on the type of array being declared.

Default Values for Different Types of Arrays

Here are the default values for some commonly used types:

1. Default value for int[] array:

0 – An array of integers will have each element initialized with the default value of 0.

2. Default value for double[] array:

0.0 – An array of doubles will have each element initialized with the default value of 0.0.

3. Default value for boolean[] array:

false – An array of booleans will have each element initialized with the default value of false.

4. Default value for char[] array:

‘u0000’ – An array of characters will have each element initialized with the default value of ‘u0000’ (null character).

5. Default value for Object[] array:

null – An array of objects will have each element initialized with the default value of null, indicating no reference is assigned to that element.

6. Default value for String[] array:

null – An array of strings will have each element initialized with the default value of null, indicating no string object is assigned to that element.

7. Default value for byte[] array:

0 – An array of bytes will have each element initialized with the default value of 0.

8. Default value for short[] array:

0 – An array of shorts will have each element initialized with the default value of 0.

9. Default value for long[] array:

0 – An array of longs will have each element initialized with the default value of 0.

10. Default value for float[] array:

0.0 – An array of floats will have each element initialized with the default value of 0.0.

11. Default value for a user-defined object[] array:

null – An array of user-defined objects will have each element initialized with the default value of null, indicating no object of that type is assigned to that element.

12. Default value for a multidimensional array:

The default value of the array type. For example, a 2-dimensional array of integers will have each element initialized with the default value of 0.

Frequently Asked Questions:

1. Can an array have a default value other than the ones mentioned above?

No, in Java, the default values for arrays are fixed and cannot be changed.

2. What happens if I access an element of an array without initializing it?

If you access an element of an array without initializing it, you will get the default value for that particular data type as mentioned above.

3. How can I assign a different default value to an array element?

You can explicitly assign a different value to an array element after it has been initialized with the default value.

4. What is the default value of an array of boolean objects?

The default value of an array of boolean objects is null.

5. What is the default value of an array of double objects?

The default value of an array of double objects is null.

6. Can I assign a non-null default value to an array element?

No, the default values for arrays are automatically assigned and cannot be changed to a non-null value.

7. How can I check if an element in an array has the default value?

You can compare the element with the default value specific to its data type using the appropriate comparison operator.

8. What is the default value of an array of characters?

The default value of an array of characters is ‘u0000’ (null character).

9. Are default values assigned to all dimensions of a multidimensional array?

Yes, all dimensions of a multidimensional array are assigned default values according to their respective data types.

10. What is the default value of an array of longs?

The default value of an array of longs is 0.

11. Can the default value of an array be changed during runtime?

No, the default values of an array are assigned at the time of initialization and cannot be changed afterwards.

12. What happens if I try to access an unassigned element in an array?

If you try to access an unassigned element in an array, you will get the default value of that particular data type as the result.

In conclusion, the default value of an array in Java depends on the data type of the array. Understanding the default values is essential for proper initialization and usage of arrays in Java.

Dive into the world of luxury with this video!