An array is a collection of similar type of elements stored in contiguous memory locations. Arrays in Java have fixed sizes and elements can be accessed via indexes. The main advantages of arrays are code optimization through efficient data retrieval and sorting. The main disadvantage is that arrays have fixed sizes set at creation time. There are single dimensional and multidimensional arrays, with single dimensional arrays being the simplest form where elements are stored in a single list.
An array is a collection of similar type of elements stored in contiguous memory locations. Arrays in Java have fixed sizes and elements can be accessed via indexes. The main advantages of arrays are code optimization through efficient data retrieval and sorting. The main disadvantage is that arrays have fixed sizes set at creation time. There are single dimensional and multidimensional arrays, with single dimensional arrays being the simplest form where elements are stored in a single list.
An array is a collection of similar type of elements stored in contiguous memory locations. Arrays in Java have fixed sizes and elements can be accessed via indexes. The main advantages of arrays are code optimization through efficient data retrieval and sorting. The main disadvantage is that arrays have fixed sizes set at creation time. There are single dimensional and multidimensional arrays, with single dimensional arrays being the simplest form where elements are stored in a single list.
An array is a collection of similar type of elements stored in contiguous memory locations. Arrays in Java have fixed sizes and elements can be accessed via indexes. The main advantages of arrays are code optimization through efficient data retrieval and sorting. The main disadvantage is that arrays have fixed sizes set at creation time. There are single dimensional and multidimensional arrays, with single dimensional arrays being the simplest form where elements are stored in a single list.
An array is a collection of similar type of elements which have a
contiguous memory location.
We can store only a fixed set of elements in a Java array.
Array in Java is index-based, the first element of the array is stored at the 0th index, 2nd element is stored on 1st index and so on. Advantages & Disadvantages
Advantages
•Code Optimization: It makes the code optimized, we can retrieve or sort the data efficiently. •Random access: We can get any data located at an index position.
Disadvantages Size Limit: We can store only the fixed size of elements in the array. It doesn't grow its size at runtime. Types of Array in java
There are two types of array.
Single Dimensional Array Multidimensional Array Single Dimensional Array in Java Syntax to Declare a Single Dimensional Array in Java
dataType []arr; Example : int []arr; OR
dataType arr[]; Example : int arr[];
Instantiation of an Array in Java
arrayReference Variable = new datatype[size];
Example : arr=new int[5];
Declaration and Instantiation together int arr[]= new int[5]; //Java Program to illustrate how to declare, instantiate, initialize
//and traverse the Java array.
class Testarray{ 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; //traversing 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 We can declare, instantiate and initialize the java array together by: int a[]={33,3,4,5};//declaration, instantiation and initialization //Java Program to illustrate the use of declaration, instantiation //and initialization of Java array in a single line class Testarray1{ public static void main(String args[]){ int a[]={33,3,4,5};//declaration, instantiation and initialization //printing array for(int i=0;i<a.length;i++)//length is the property of array System.out.println(a[i]); }} Output:
33 3 4 5 What happens if we try to access element outside the array size?
JVM throws ArrayIndexOutOfBoundsException to
indicate that array has been accessed with an illegal index. The index is either negative or greater than or equal to size of array. class Testarray{ public static void main(String args[]){ int a[]=new int[2];//declaration and instantiation a[0]=10;//initialization a[1]=20; //traversing array for(int i=0;i<=a.length;i++) System.out.println(a[i]); Runtime error Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2 at GFG.main(File.java:12)
Output 10 20 How to read values into an array using for loop import java.util.*; public class arr1 { public static void main() { System.out.println("elements of array a[]"); int a[]= new int[10]; for(i=0;i<10;i++) int i; { Scanner sc=new Scanner(System.in); System.out.print(a[i]+"\t"); System.out.println("enter } numbers"); } for(i=0;i<10;i++) } { a[i]=sc.nextInt(); }
