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Vignesh . M
Vignesh . M

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ARRAY IN JAVA

#java #programming #webdev

What is array in java?

  • In Java, an array is a fundamental data structure that serves as a container object holding a fixed number of values of a single type. These values are stored in contiguous memory locations and are accessed using a zero-based index.

Why array using in java?

  • Arrays are used in Java for several key reasons, primarily to efficiently manage and store collections of data of the same type:

Key features of Arrays:

Contiguous Memory Allocation (for Primitives):

  • Java array elements are stored in continuous memory locations, which means that the elements are placed next to each other in memory.

Zero-based Indexing:

  • The first element of the array is at index 0.

Fixed Length:

  • Once an array is created, its size is fixed and cannot be changed.

Can Store Primitives & Objects:

  • Java arrays can hold both primitive types (like int, char, boolean, etc.) and objects (like String, Integer, etc.)

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Basics of Arrays in Java

  • There are some basic operations we can start with as mentioned below:

1. Array Declaration

  • To declare an array in Java, use the following syntax: 
type[] arrayName;
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type: The data type of the array elements (e.g., int, String).
Arrayname: The name of the array.
Note: The array is not yet initialized.

2. Create an Array

  • To create an array, you need to allocate memory for it using the new keyword: 
// Creating an array of 5 integers
int[] numbers = new int[5];
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This statement initializes the numbers array to hold 5 integers. The default value for each element is 0.

3. Access an Element of an Array

  • We can access array elements using their index, which starts from 0: 
// Setting the first element of the array
numbers[0] = 10; 

// Accessing the first element
int firstElement = numbers[0];
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The first line sets the value of the first element to 10. The second line retrieves the value of the first element.

4. Change an Array Element
* To change an element, assign a new value to a specific index:

// Changing the first element to 20
numbers[0] = 20;
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5. Array Length

  • We can get the length of an array using the length property: 
// Getting the length of the array
int length = numbers.length;
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sample program for array string

public class Example {

    public static void main(String[] args) {
        String[] myArray = {"foo", "bar", "baz"};

        // retrieval
        System.out.println(myArray[0]);
        System.out.println(myArray[1]);
        System.out.println(myArray[2]);
    }
}
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REFFERED LINKS
1.https://www.geeksforgeeks.org/java/arrays-in-java/
2.https://opensource.com/article/22/11/arrays-java

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