What Happens When Java Array Length is Less Than Zero?

What happens if a Java array has a length less than zero?

int[] array = new int[-5]; // This code will throw an IllegalArgumentException

In Java, array lengths must always be non-negative. Attempting to create an array with a negative length will result in a runtime exception. Here’s a detailed breakdown of the concept and how to handle related issues.

try {
    int[] array = new int[-5];
} catch (NegativeArraySizeException e) {
    System.out.println("Negative array size: " + e);
}

Causes

• Attempting to initialize an array with a negative size using `new int[-5]` results in an IllegalArgumentException.
• Miscalculated indices or incorrect logic in array initialization can lead to attempts at creating an array of negative length.

Solutions

• Always validate the size used for array initialization to ensure it's non-negative before creating the array.
• Use Java's built-in tools or unit tests to check your program's logic for potential negative sizes.

Mistake: Directly providing user input as the size for an array without validation.

Solution: Always validate user input to check if it's a non-negative integer before usage.

Mistake: Confusing array size with its index. Indices are zero-based, but size must be quantified correctly.

Solution: Keep a clear distinction between the length of an array and the indices used for accessing array elements.