Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Java Program to Convert Collection into Array
In this article, we will understand how to convert collection into array. The Collection is a framework that provides architecture to store and manipulate the group of objects. Java Collections can achieve all the operations that you perform on a data such as searching, sorting, insertion, manipulation, and deletion.
Below is a demonstration of the same −
Suppose our input is −
Input list: [Java , program , is , fun]
The desired output would be −
The result after converting to an array is: Java program is fun
Algorithm
Step 1 - START Step 2 - Declare a list namely input_list, a string array namely result_string. Step 3 - Define the values. Step 4 - Convert the list to an array of strings by assigning input_list.toArray(new String[0]) to the result_string array. Step 5 - Display the result. Step 6 - Stop
Example 1
Here, we bind all the operations together under the ‘main’ function.
import java.util.ArrayList;
import java.util.*;
public class Demo {
public static void main(String[] args){
System.out.println("Required packages have been imported");
List<String> input_list = new ArrayList<String>();
input_list.add("Java ");
input_list.add("program ");
input_list.add("is ");
input_list.add("fun");
System.out.println("The list is defined as:" + input_list);
System.out.println("\nThe result after converting to an array is:");
String[] result_string = input_list.toArray(new String[0]);
for (int i = 0; i < result_string.length; i++) {
String element = result_string[i];
System.out.print(element);
}
}
}Output
Required packages have been imported The list is defined as:[Java , program , is , fun] The result after converting to an array is: Java program is fun
Example 2
Here, we encapsulate the operations into functions exhibiting object oriented programming.
import java.util.ArrayList;
import java.util.*;
public class Demo {
static void convert_to_array(List<String> input_list){
System.out.println("\nThe result after converting to an array is:");
String[] result_array = input_list.toArray(new String[0]);
for (int i = 0; i < result_array.length; i++) {
String element = result_array[i];
System.out.print(element);
}
}
public static void main(String[] args){
System.out.println("Required packages have been imported");
List<String> input_list = new ArrayList<String>();
input_list.add("Java ");
input_list.add("program ");
input_list.add("is ");
input_list.add("fun");
System.out.println("The list is defined as:" + input_list);
convert_to_array(input_list);
}
}Output
Required packages have been imported The list is defined as:[Java , program , is , fun] The result after converting to an array is: Java program is fun
Updated on: 30-Mar-2022
431 Views
Advertisements