Core Java Tutorial

Introduction of Core Java

How To Install JDk and Set of Path

Syntax of java Program

Difference between Java and C/C++

Advantage and Disadvantage of Java

What is Java

Why Java is not Pure Object Oriented Language

Java has Following Features/Characteristics

Limitation of Java Language and Java Internet

Common Misconception about Java

Simple Program of Java

Integrated Development Environment in java

Compile and Run Java Program

Applet and Comments in Java

Tokens in Java

Keywords in Java

Identifier and Variables in Java

Literals/Constants

Data Type in Java

Assignments and Initialization in Java

Operators in Java

Rule of Precedence in Java

Operator on Integer and Separators in Java Programming

Java Control Flow of Statements

If and If-else Selection Statement

Nested If-else and If-else-If Selection Statement

switch case and conditional operator Selection Statement

for and while Loop

do..while and for each Loop

break and labeled break statement

continue and labeled continue statement

return Statement and exit() Method

Escape Sequence for Special Characters and Unicode Code

Constants and Block or Scope

Statement in Java

Conversions between Numeric Types in Java

Import Statement in Java

User Input in Java using Scanner Class

User Input in Java using Console Class

Array in Java

One Dimensional Array

Two Dimensional Array

Two Dimensional Array Program

Command Line Argument in Java

String args Types in Java

Uneven/Jagged array in java

Math Class Function and Constant

Math Class all Function used in a program

Enumerated Types in Java

Object Oriented Programming v/s Procedural Programming

Object Oriented Programming Concepts in Java

Introduction to Class,Object and Method in Java

Class Declaration in Java

Class & Objects in java

Encapsulation in Java

Modifiers/Visibility for a Class or Interrface or member of a Class

Polymorphism in Java

Runtime polymorphism (dynamic binding or method overriding)

how to convert LinkedList to simple Array using Collections in java

how to convert LinkedList to simple Array using Collections in java

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In this example we will see how can we convert a LinkedList to a linear Array.

In this example we have created a class CollectionExample. For using LinkedList we have
to import the java.util package.
 In this example we have used the toArray() method defined in the java.util package. The syntax of the toArray() method used in the following example is,

toArray(Anytypearray[] array)
This method returns an array containing all of the elements of the list in its order; the runtime type of the returned array is that of the specified array.

In the following example we have created a LinkedList named list. We also created an Integer array that is exactly of same size as that of the list, which is done by the following statement,
Integer[] arr=new Integer[list.size()];  

Then we have used the toArray(Anytypearray[] array) method on the list and stored all the elements of the list to the Integer array named arr. Finally we have diaplayed the elements of the array(which is created i.e arr) using the for loop.

 
package r4r.co.in;
import java.util.*;
import java.util.ListIterator;



public class CollectionExample {

/**
* @param args
*/
public static void main(String[] args)
{
// TODO Auto-generated method stub


LinkedList<Integer> list=new LinkedList<Integer>(); // creating a LinkedList of Object type elements
list.add(1); // adding integer values to the LinkedList
list.add(2);
list.add(50); // adding String values to the LinkedList
list.add(70);
list.add(7);
System.out.println("The contents of the list are :");
ListIterator<Integer> ltr=list.listIterator();
while(ltr.hasNext())
{
System.out.println(ltr.next()); // displaying the contents of the list
}

list.set(2, 700); // replacing the value contained at index 2 by 700
System.out.println("After replacing the value at the index 2 we have the list as:");
System.out.println(list); // now displaying the list elements after replacing the element
Integer[] arr=new Integer[list.size()]; // creating an Integer array of same size as that of the list
arr=list.toArray(arr); //converting the linkedlist list to array
System.out.println("The elements of the array are as follows:");
for(int i=0;i<arr.length;i++)
System.out.println(arr[i]); // displaying the contents of the array


}


}
The output of the above written program is as follows:

The contents of the list are :
1
2
50
70
7
After replacing the value at the index 2 we have the list as:
[1, 2, 700, 70, 7]
The elements of the array are as follows:
1
2
700
70
7

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