Arrays of Primitive Types in Java

In Java, arrays are used to store a fixed-size collection of elements of the same data type. An array can be of primitive types or reference types (objects). Let’s focus on arrays of primitive types in Java.

Declaration and Initialization

To declare an array of primitive types, we specify the data type followed by square brackets []:

// Declaration
int[] intArray;

// Initialization (with a fixed size of 5)
intArray = new int[5];

Alternatively, we can declare and initialize an array in a single line:

int[] intArray = new int[]{1, 2, 3, 4, 5};
// or
int[] intArray = {1, 2, 3, 4, 5};

Accessing Elements

Array elements are accessed using the index, starting from 0. For example:

int firstElement = intArray[0]; // Access the first element
int thirdElement = intArray[2]; // Access the third element

Length of the Array

We can get the length of an array using the length property:

int arrayLength = intArray.length;

Arrays are Fixed Size

In Java, arrays have a fixed size, which means once an array is created, its size cannot be changed. If we need a dynamic collection, then we can use other data structures like ArrayList.

Default Values

When an array of primitive types is created, its elements are initialized with default values based on their data type:

• int, short, byte, long: 0
• float, double: 0.0
• char: ‘\u0000’ (null character)
• boolean: false

Looping through Array

We can use loops (e.g., for loop) to iterate through the elements of the array:

for (int i = 0; i < intArray.length; i++) {
    int element = intArray[i];
    // Do something with the element
}

Remember that arrays in Java are zero-indexed, which means the first element is at index 0, the second element is at index 1, and so on. Also, be cautious about accessing elements outside the valid index range, as it may result in an ArrayIndexOutOfBoundsException.

Frequently Asked Questions