08 Arrays
8.1 | Arrays
An array is a data structure that stores a collection of values of the same data type. Values stored in the array are accessible through the array index
//Declaring an array of integers
int arr1[];
//Creating an integer array with values
int[] arr0 = {2,3,4,5,6,7};
//Creating an integer array which can hold 100 integers
int arr2[] = new int[100];
//Or,
int arraySize = 100;
int arr3[] = new int[arraySize];
//Assigning values to the array
arr3[0] = 1;
arr3[1] = 2;
//Creating a string array which can hold 100 values
String arr4[] = new String[100];
//Assigning values to the array
arr4[0] = “This”;
arr4[1] = “is a string array by”;
arr4[2] = “testinganswers.com”;
//Accessing array values by using for loop
for(int i=0;i<arr3.length; i++){
System.out.println(“arr3[“+i+”] = “+arr3[i]);
}
//Or by using for each loop,
for(int element:arr3){
System.out.println(element +”,”);
}
//Copying array
int[] arr5 = arr3;
String[] arr6 = arr4;
8.1.1 | Multi-dimensional Arrays
Multi-dimensional arrays are arrays of an array. They use more than one index to store and access values.
//Declaring a multi-dimensional array
int[][] arr0;
//Creating a multi-dimensional array
int[][] arr1 = {
{1,2,3}
{4,5,6}
{7,8,9}
};
//Creating a multi-dimensional array of size 2*3
int[][] arr2 = new int[2][3];
//Creating a multi-dimensional array using variables
int arrayXsize = 3;
int arrayYsize = 3;
int[][] arr3 = new int[arrayXsize][arrayYsize];
//Assigning values to multi-dimensional arrays
arr3[0][0] = 1;
arr3[0][2] = 3;
//Accessing values from multi-dimensional arrays
for(int i=0;i<arr2.length;i++){
for(int j=0;j<arr2[i].length;j++){
System.out.println(“arr2[“+i+”][“+j+”] = “+arr2[i][j]);
}
}
//Copying multi-dimensional arrays
int[][] arr4 = arr3;