Java Array

Java Array

Java Array

An array is collection of objects and all the objects have the same name. Each object is called an element. The elements are numbered as 0, 1, 2,…, n-1. These numbers are called as indices or subscripts. These numbers are used to locate the positions of elements within the array.

The method of numbering the ith element with index i-1 is called as zero-based indexing. That is, the element is always same as the number of “steps” from the initial element a[0] to that element. For example, the element a[3] is 3 steps from the element a[0].

Array can Strore data in index based and it can store only homogeneous data. Once we create an array we cannot chage the array size (increase or decrease) at run time. we can retrieve or store the data based on index and we can store huge data with the same name.Readability is easy.


Int[] array=new int[10];

Int[] array={10,20,30,40,40};

In the above mentioned ways we can create arrays.

array[0] – it will return 10.because 0 th index 10 value is there.

Types of arrays

There are three types of arrays.

  • One-dimensional array
  • Two-dimensional array
  • Multi-dimensional array

One-dimensional array

It is an array in which each element is accessed by using only one subscript. The only one subscript represents the position of the element in the array.

Declaration of one-dimensional array


datatype    array-name[size];

Example :

 int     marks[50];

Initialization of one-dimensional arrays

We can give values to each array element when the array is first defined.

Example :

int a[5] = {9, -5, 6, 2, 8};

In the above example, value 9 is stored in a[0], value -5 is stored in a[1], value 6 is store in a[2], value 2 is stored in a[3] and value 8 is store in a[4].

Memory representation of one-dimensional arrays:

The elements of one-dimensional arrays are stored in contiguous memory locations.


Consider the declaration,   char a[5];

The element a[0] is allocated at a particular memory location, the element a[1] is allocated at next memory location and so forth. Since the array is of the type char, each element requires 1-byte.

Multi-dimensional array

A multidimensional array is an array of n-dimensions. In other words, an array of arrays is called a multidimensional array. A one-dimensional array of one-dimensional arrays is called a two-dimensional array; a one-dimensional array to two-dimensional arrays is called a three-dimensional array and so on.

Three steps to create an array:

  • Declare a variable to hold the array.
  • Create a new array object and assign it to the array variable.
  • Store things in that array.


String[] names;
names = new String[10];
names [1] = “n1”;
names[2] = ‘n2’;

. . .

Java does not support multidimensional arrays. However, we can declare and create an array of arrays and access them as you would C-style multidimensional arrays.

Creating Arrays

For create an array we can use the new operator with the below syntax:

Array RefVar = new dataType[arraySize];

Passing Array to Methods

Just as we can pass original type values to methods, We can also pass arrays to methods.

Passing Array to Methods


Returning an Array from Methods

This method shown below returns an array that is the reversal of another array:

Array from a Method


The Array Class

The java.util.Arrays class contains different static strategies for arranging and seeking arrays, looking at arrays, and filling array components. These strategies are over-burden for every crude sort.

Strategies with Description

public static int binary Search(Object[] an, Object key)

Ventures the predefined array of Object ( Byte, Int , twofold, and so on.) for the predetermined esteem utilizing the double pursuit calculation. The array must be arranged preceding making this call. This profits file of the pursuit key, on the off chance that it is contained in the rundown; generally, (‐(insertion point + 1).

public static Boolean equals(long[] a, long[] a2)

Returns genuine if the two indicated arrays of yearns are equivalent to each other. Two arrays are viewed as equivalent if both arrays contain a similar number of components, and every single comparing pair of components in the two arrays are equivalent. This profits genuine if the two arrays are equivalent. Same technique could be utilized by all other crude information types (Byte, short, Int, and so on.)

public static void fill(int[] an, int val)

Doles out the predetermined int incentive to every component of the predefined array of ints. Same strategy could be utilized by all other crude information types (Byte, short, Int and so forth.)

public static void sort(Object[] a)

Sorts the predetermined array of items into rising request, as indicated by the common requesting of its components. Same strategy could be utilized by all other crude information types ( Byte, short, Int, and so on.)

Besant Technologies – Chennai & Bangalore Branch Locations

Besant Technologies - Velachery Branch
Plot No. 119, No.8, 11th Main road, Vijaya nagar,
Velachery, Chennai - 600 042
Tamil Nadu, India
Landmark - Reliance Digital Opposite Street
+91-996 252 8294 / 996 252 8293

Besant Technologies - Tambaram Branch
No.2A, 1st Floor, Duraisami Reddy Street,
West Tambaram, Chennai - 600 045
Tamil Nadu, India
Landmark - Near By Passport Seva
+91-970 725 0260

Besant Technologies - OMR Branch
No. 5/318, 2nd Floor, Sri Sowdeswari Nagar,
OMR, Okkiyam Thoraipakkam, Chennai - 600 097
Tamil Nadu, India
Landmark - Behind Okkiyampet Bus Stop,
+91-887 038 4333

Besant Technologies - Porur Branch
No. 180/84, 1st Floor, Karnataka Bank Building
Trunk Road, Porur,
Chennai - 600 116
Tamilnadu, India
Land Mark: Opposite to Gopalakrishna Theatre
+91-755 022 6990

Besant Technologies - Anna Nagar Branch
Plot No:1371, 28th street kambar colony,
I Block, Anna Nagar ,
Chennai - 600 040
Tamil Nadu, India
Landmark - Behind Reliance Fresh
+91-938 404 0493

Besant Technologies - T.Nagar Branch
Old No:146/2- New No: 48,
Habibullah Road,T.Nagar,
Chennai - 600 017
Tamil Nadu, India
Landmark - Opposite to SGS Sabha
+91-984 025 8377

Besant Technologies - Thiruvanmiyur Branch
22/67, 1st Floor,
North mada street, Kamaraj Nagar
Thiruvanmiyur, Chennai 600041
Tamil Nadu, India
Landmark - Above Thiruvanmiyur ICICI Bank
+91-938 404 0493

Besant Technologies - Siruseri Branch
No. 4/76, Ambedkar Street,
OMR Road, Egatoor, Navallur,
Siruseri, Chennai 600130
Tamil Nadu, India
Landmark - Near Navallur Toll Gate, Next to Yamaha Showroom
+91-7338 810 550

Besant Technologies - Maraimalai Nagar Branch
No.37, Ground Floor,
Thiruvalluvar Salai,
Maraimalai Nagar,Chennai 603209
Tamil Nadu, India
Landmark - Near to Maraimalai Nagar Arch
+91-979 123 7373

Besant Technologies - BTM Layout Branch
No 2, Ground floor,
29th Main Road, Kuvempu Nagar,BTM Layout 2nd Coming from Silkboard, take left at AXA company signal,
Stage, Bangalore - 560 076
Karnataka, India
Landmark - Next to OI Play School
+91-762 494 1772 / 74

Besant Technologies - Marathahalli Branch
No. 43/2, 2nd Floor, VMR Arcade,
Varthur Main Road, Silver Springs Layout,
Munnekollal, Marathahalli, Bengaluru - 560037
Karnataka, India
Landmark - Near Kundalahalli Gate Signal
+91-910 812 6341

Besant Technologies - Rajaji Nagar Branch
No. 309/43, JRS Ecstasy, First Floor,
59th Cross, 3rd Block, Bashyam Circle,
Rajaji Nagar, Bangalore - 560 010
Karnataka, India
Landmark - Near Bashyam Circle
+91- 734 916 0004

Besant Technologies - Jaya Nagar Branch
No. 2nd Floor,1575,11th Main Road,
4th T-Block, Pattabhirama Nagar, Jaya Nagar,
karnataka, India
Land Mark: Opposite to Shanthi Nursing Home
+91-733 783 7626

Besant Technologies - Kalyan Nagar Branch
No.513, 4th Cross Rd
2nd Block, HRBR Layout, Kalyan Nagar,
karnataka, India
Land Mark: Opposite to kalayan nagar Axis Bank
+91-938 404 0495

Besant Technologies - Electronic City Branch
No. 7, 3rd Floor, Ganga Enclave,
Neeladri Road, Karuna Nagar, Doddathoguru Village,
Electronics City Phase 1, Electronic City,
Bangalore - 560100, karnataka, India
Land Mark: Adjacent to HDFC Bank and State Bank Of India
+91-782 392 2180

Besant Technologies - Indira Nagar Branch
No.54, 1st Floor,
5th Main kodihalli,
Bengaluru, Karnataka 560008, India
Landmark: Behind Leela Palace Hotel,
+91-910 812 6339

Besant Technologies - HSR Layout Branch
Plot No. 2799 & 2800, 27th Main,
1st Sector, HSR Layout,
Bengaluru, Karnataka 560102, India
+91-733 783 7626

Besant Technologies - Hebbal Branch
No.29, 2nd Floor, SN Complex,
14th Main Road, E-Block Extention, Sahakara Nagar,
Bengaluru, Karnataka -560092, India
+91-938 404 0496