Single & Multi-Dimensional Arrays in Java

 

 

 

Through this blog we are going to learn about java array. Many important concepts like single dimensional arrays, multi-dimensional arrays along with their working will be explained in this blog.

 

 

 

 

·      What are Arrays?

       An array is a data structure, which can store a fixed-                 size collection of elements of the same data type.

An array could a collection of comparable  kind of elements which have contiguous memory locations. Array contains the elements which are homogenous in nature. Arrays are capable of storing one or more values of a specific data type and also supply indexed access to store the same. Any element in an array is accessed by a number assigned to it according it’s position which is known as its index. Arrays are the best way to store the related information together.

      

·      Arrays in java:

Java array is an object which contains elements of same  data type. Also, the elements of an array are stored in a contiguous memory locations, i.e is one after the other. We are able to store only a fixed set of elements in a Java array. Arrays are dynamically allocated in java.

·      Dynamic Array in Java

The limitation of arrays is that they are fixed in size. It means  we must specify the quantity of elements while declaring the array.

      

A question arises that what if we wish to insert a component and there is no more space is left for the new element? Here, the concept of a dynamic array comes into consideration. It expands the dimensions of the array dynamically.

 The dynamic array may be a variable size list organization. It grows automatically once we attempt to insert a component if there is no more extra space left for the new component. It allows us to add and remove elements. A dynamic array is capable of allocating the memory during runtime using heap. It can change its size during run time.

 

 

 

Working of Dynamic Array

 

In the dynamic array, the components are stored contiguously from the starting of the array and the remaining space remains unused. We are able to add the elements until the reserved spaced is totally used. When the reserved space is consumed and required to feature some elements. In such a case, the fixed-sized array must be increased in size.

 

Types of arrays:

• Single Dimensional Array

Single dimensional array consists of one row or one column of array elements that share a typical name and are recognized by their index values that are assigned to them.

For example, consider this , a single dimensional array can be used to store the marks scored by a student in five subjects, since this marks can be written in  one row or one column. This marks can be accessed using the index assigned to them by writing it in square brackets preceded by the name of that array.

Here’s how to declare and create single-dimensional array java.

 

 

 

int[] marks; //Declaration!

marks = new int[5]; //Memory allocation!

 int[] marks = new int[5]; //Declaration + Memory allocation!

 int[] marks = {100,70,80,71,98} // Declare + Initialize!

 

 

 

• Multidimensional Array

An array with multiple rows and columns is known as a multi-dimensional array. A multi-dimensional array is capable of holding more than one row and column. Data is accessed using row column index. A matrix is a perfect example of a multidimensional array.

Syntax:

datatype [1][2]…[nth dimension] arrayname = new datatype[1][2]…[nth size];

Here’s how we can declare and create 2-dimensional array java.

int [][] flats = new int[2][3]

int[][] b = {{1,2,3,4},{5,6,7,8},{9,10,11,12}};