How to Declare and Initialize an Array in Java?

What are the steps to declare and initialize an array in Java?

int[] numbers = new int[5]; // Declaration
numbers[0] = 10; // Initialization
// or
int[] numbers = {10, 20, 30, 40, 50}; // Declaration and initialization

In Java, arrays are used to store multiple values of the same type in a single variable. Here’s how you can declare and initialize arrays effectively.

// Declaring an array
int[] numbers = new int[5]; // Declaration (size = 5)
// Initializing the array
for (int i = 0; i < numbers.length; i++) {
    numbers[i] = i * 10; // Assigning values
}
// Outputting array values
System.out.println(Arrays.toString(numbers)); // [0, 10, 20, 30, 40]
// Using a shorthand initialization
int[] anotherArray = {1, 2, 3, 4, 5}; // Declaration and initialization in one step

Causes

• Understanding data storage in Java: Why use arrays?
• Syntax differences between declaration and initialization.

Solutions

• Use the correct syntax: int[] arrayName; for declaration.
• Initialize with the 'new' keyword or using curly braces.

Mistake: Forgetting to specify the size when declaring an array.

Solution: Always include a size or use an initializer list to avoid compiler errors.

Mistake: Accessing an array index out of bounds.

Solution: Always check the array length before accessing an index to prevent ArrayIndexOutOfBoundsException.