There are two ways to declare and initialize an array in Java:

1. Declare and initialize the array in one step. This can be done by using the following syntax:

data_type[] array_name = {value1, value2, value3, ...};

where data_type is the data type of the elements of the array, array_name is the name of the array, and value1, value2, value3, ... are the initial values of the array elements.

For example, the following code declares and initializes an array of integers:

int[] numbers = {1, 2, 3, 4, 5};

1. Declare the array and then initialize the elements one by one. This can be done by using the following syntax:

data_type[] array_name;

array_name = new data_type[size];

array_name[0] = value1;
array_name[1] = value2;
array_name[2] = value3;
...

where size is the size of the array.

For example, the following code declares an array of integers and then initializes the elements one by one:

int[] numbers;

numbers = new int[5];

numbers[0] = 1;
numbers[1] = 2;
numbers[2] = 3;
numbers[3] = 4;
numbers[4] = 5;

Which method you use to declare and initialize an array depends on your specific needs. If you know the initial values of the array elements, then it is more efficient to declare and initialize the array in one step. However, if you do not know the initial values of the array elements, then you will need to declare the array and then initialize the elements one by one.