Arrays

Array:

• Array is a collection of similar type of elements that have contiguous memory location.
• In java, array is an object the contains elements of similar data type. 
• It is a data structure where we store similar elements. 
• We can store only fixed elements in an array.
• Array is index based, first element of the array is stored at 0 index.

Example: 

class Array{  

public static void main(String args[]){  

  

int a[]=new int[5];//declaration and instantiation  

a[0]=10;//initialization  

a[1]=20;  

a[2]=70;  

a[3]=40;  

a[4]=50;  

  

//printing array  

for(int i=0;i<a.length;i++)//length is the property of array  

System.out.println(a[i]);  

  

}}  

Output: 10

       20

       70

       40

       50

Advantage of Array

• Code Optimization: It makes the code optimized, we can retrieve or sort the data easily.
• Random access: We can get any data located at any index position.
• Insertion, deletion and updation is easy.

Disadvantage of Array

Size Limit: We can store only fixed size of elements in the array. It doesn't grow its size at runtime. To solve this problem, collection framework is used in java.

Types of Array

• Single Dimensional Array

                 Example:  int a[]={33,3,4,5};//declaration, instantiation and initialization  

• Multidimensional Array

               Example:  int[][] arr=new int[3][3];//3 row and 3 column