Java List toArray() Method with Examples

by Online Tutorials Library July 22, 2022

Java List toArray() Method

The toArray() method of List interface returns an array containing all the elements present in the list in proper order.

The second syntax returns an array containing all of the elements in this list where the runtime type of the returned array is that of the specified array.

Syntax

Parameters

NA
The parameter ‘a’ represents the array in which the elements of the list will be stored.

Type Parameters

The type parameter ‘T’ represents the component type of the array to hold the collection.

Return Value

The toArray() method returns an array that contains all the elements of this list in proper order.

Specified by

toArray() in interface Collection<E>

Throws:

ArrayStoreException– If the runtime type of the specified array is not a supertype of the runtime type of every element in this list.

NullPointerException– If the defined array is null.

Example 1

  import java.util.LinkedList;  import java.util.List;  public class JavaListToArrayExample1 {  static int j=1;  public static void main(String[] args) {          List<Character> list = new LinkedList<>();  for (char i=’a’;i<=’z’;i++) {  list.add(i);          }  System.out.print(“Alphabet : “);          Object[] a=list.toArray();  System.out.println();  for(int i=0 ;i<a.length;i++){  System.out.println( j++ +”: “+ a[i]);          }      }  }  

Test it Now

Output:

Alphabet :  1: a  2: b  3: c  4: d  5: e  6: f  7: g  8: h  9: i  10: j  11: k  12: l  13: m  14: n  15: o  16: p  17: q  18: r  19: s  20: t  21: u  22: v  23: w  24: x  25: y  26: z

Example 2

  import java.util.LinkedList;  import java.util.List;  public class JavaListToArrayExample2 {  public static void main(String[] args) {          List<Integer> list = new LinkedList<>();  for (int i = 1; i <= 10; i++) {  list.add(i);          }          Object[] a = list.toArray();  for (int i = 0; i <a.length; i++) {  System.out.print(a[i] + ” “);  if (a[i] % 2 == 0) {  System.out.println(a[i] + ” is an even number.”);              }          }      }  }  

Test it Now

Output:

Error:(15, 22) java: bad operand types for binary operator '%'  first type:  java.lang.Object  second type: int

Operator ‘%’ cannot be applied to java.lang.Object. If done so it will give you an error.

Example 3

This example is the solution of the above-described program.

  import java.util.LinkedList;  import java.util.List;  public class JavaListToArrayExample3 {  public static void main(String[] args) {          List<Integer> list= new LinkedList<>();  System.out.println(“List of odd numbers in our list.”);  for (int i=1;i<=10;i++) {  list.add(i);          }          Integer[] a = new Integer[5];          Integer[] b =  list.toArray(a);  for (int i = 0; i <b.length; i++) {  if (b[i] %2!=0) {  System.out.println(b[i]+” “);              }          }      }  }  

Test it Now

Output:

List of odd numbers in our list.  1   3   5   7   9

Next TopicJava List

add()clear()contains()containsAll()equals()get hashcode()indexOf()isempty()java list ListIterator remove removeall retainall size()toArray()

Java List toArray() Method with Examples

Java List toArray() Method

Syntax

Parameters

Type Parameters

Return Value

Specified by

Throws:

Example 1

Example 2

Example 3

Java Executors newWorkStealingPool() Method

Java Boolean Keyword

You may also like