arrays

Methods of declaring an array

//How to declare an array
//Method 1
int[] anArray;
anArray = new int[10];

//Method 2
int anArray[];
anArray[] = new int[10];

//Method 3
int[] anArray = new int[10];

//Method 4
int anArray[] = new int[10];

General tips on arrays

// Declares an array with 4 elements of type String
String[] dogs = new String[4];

// This populates our array with data, notice how the array starts at 0 and ends at 3
dogs[0] = "Rex";
dogs[1] = "Sparky";
dogs[2] = "Rover";
dogs[3] = "Lassie";

// If we try to access an element that doesnt exist in our array we get an ArrayIndexOutOfBoundsException
System.out.println("The dogs name is " + dogs[4])

A simple example of an array of strings

public class ArrayExample
{
    public static void main(String args[])
    {
        // Arrays are used to store values of the same type.
        // This array is an array of String type.
        String[] month;
        month = new String[12];

        // Arrays start at an index of 0, so if there is 12 elements the first element will be 0 and the last element will be 11
        month[0] = "January";
        month[1] = "February";
        month[2] = "March";
        month[3] = "April";
        month[4] = "May";
        month[5] = "June";
        month[6] = "July";
        month[7] = "August";
        month[8] = "September";
        month[9] = "October";
        month[10] = "November";
        month[11] = "December";

        //This will print out February and not january as the index starts at 0.
        System.out.println("The month is " + month[1]);
    }
}

A simple example of an array of integers

public class IntArrayExample
{
    public static void main(String args[])
    {
            // Creating an array of integers with 10 elements
        int[] numbers;
        numbers = new int[10];

            // If u tried to insert a string or double into this array you would get an error as it will only accept integers.
        numbers[0] = 10;
        numbers[1] = 20;
        numbers[2] = 30;
        numbers[3] = 40;
        numbers[4] = 50;
        numbers[5] = 60;
        numbers[6] = 70;
        numbers[7] = 80;
        numbers[8] = 90;
        numbers[9] = 100;

        System.out.println("Your number is " + numbers[4]);
    }
}