Arrays are used to store multiple values in a single variable, instead of declaring separate variables for each value. To declare an array, define the variable type with square brackets:

Create Arrays

String[] cars;

We have now declared a variable that holds an array of strings. To insert values to it, we can use the new operator or an array literal - place the values in a comma-separated list, inside curly braces:

String[] cars = {"Volvo", "BMW", "Ford", "Mazda"}; // String Array
int[] myNum = {10, 20, 30, 40}; // Integer Array
int[] newArray = new int[5]; // Integer Array with zero (default) values

Access elements of Arrays

You access an array element by referring to the index number. This statement accesses the value of the first element in cars:

String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
System.out.println(cars[0]); // Outputs Volvo

Note: Array indexes start with 0: [0] is the first element. [1] is the second element, etc.

Change elements of Arrays

To change the value of a specific element, refer to the index number:

String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
cars[0] = "Opel";
System.out.println(cars[0]); // Now outputs Opel instead of Volvo

Array Length

To find out how many elements an array has, use the length property:

String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
System.out.println(cars.length); // Outputs 4

Loop Through an Array

You can loop through the array elements with the for loop, and use the length property to specify how many times the loop should run. The following example outputs all elements in the cars array:

String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};
for (int i = 0; i < cars.length; i++) {

Multidimensional Arrays

A multidimensional array is an array containing one or more arrays. To create a two-dimensional array, add each array within its own set of curly braces:

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };

To access the elements of the myNumbers array, specify two indexes: one for the array, and one for the element inside that array. This example accesses the third element (2) in the second array (1) of myNumbers:

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
int x = myNumbers[1][2];
System.out.println(x); // Outputs 7

We can also use a for loop inside another for loop to get the elements of a two-dimensional array (we still have to point to the two indexes):

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
for (int i = 0; i < myNumbers.length; i++) {
    for(int j = 0; j < myNumbers[i].length; j++) {


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