An array is an ordered collection of elements of the same type, identified by a pair of square brackets [].To use an array, you need to:1.Declare the array witha name and a type. Use a plural name for array, e.g., marks, rows,numbers. All elements of the array belong tothe same type.2.Allocate the array using new operator, or through initialization, e.g.int[] marks;// Declare an int array named marks// marks contains a special value called null.int marks[];// Same as above, but the above syntax recommended
marks =newint[5];// Allocate 5 elements via the "new" operator// Declare and allocate a 20-element array in one statement via "new" operatorint[] factors =newint[20];// Declare, allocate a 6-element array thru initializationint[] numbers ={11,22,33,44,55,66};// size of array deduced from the number of items
// How to use arrays // Julianpublicstaticvoidmain(String[] args){// Initialize arrayint[] arrNum ={25,23,15,20,24};// Recorrerlofor(int a =0; a < arrNum.length; a++){System.out.println(arrNum[a]);}}
//1-dimensional array 10int array[]=newint[10];//2-dimensional array 10x5int array[][]=newint[10][5];///*
| Or it can also be declared by setting some values |
| The dimensions of the array will be obtained |
| automatically by the compiler according to the declaration |
*/int array[]={1,2,3,4,5,6};//---> new array[6] //--- the value of array[0] is 1// | the value of array[1] is 2// ...//--- the value of array[5] is 6int array[][]={{1,2,3,4},{5,6,7,8},{9,10,11,12}};//---> array[3][4]
Java array is an object which contains elements of a similar data type.
Additionally,The elements of an array are stored in a contiguous memory
location.
Basically, it is one of the a data structure where we store similar elements.
We can store only a fixed set of elements in a Java array.
following shows the use of the array in java,int a[]=newint[5];//declaration and instantiation
a[0]=10;//initialization
a[1]=20;//after printing arraydefault value of arrray element is 0;[10,20,0,0,0]
String[] cars ={"Volvo","BMW","Ford","Mazda"};System.out.println(cars[0]);// Change elements in array
cars[0]="Opel";System.out.println(cars[0]);// Length of arraySystem.out.println(cars.length);// Loop through arrayfor(int i =0; i < cars.length; i++){System.out.println(cars[i]);}