Java Long class

Java Collections singletonList() Method

Last Updated : 17 Mar 2025

The singletonList() method of Java Collections class is used to get an immutable list which contains only the specified object.

Syntax

Following is the declaration of singletonList() method:

Parameter

Parameter	Description	Required/Optional
o	It is the object which will be stored in the returned List.	Required

Returns

The singletonList() method returns an immutable List which contains only the specified object.

Exceptions

Compatibility Version

Java 1.3 and above

Example 1

import java.util.*;
public class CollectionsSingletonListExample1 {
	public static void main(String[] args) {
	    List<Integer> numList = Collections.singletonList(10); 	 
	    System.out.println("Number List elements: " + numList);	 
	    //numList.add(20);       // throws UnsupportedOperationException	 
	    List<String> strList = Collections.singletonList("Hello India"); 
	    System.out.println("String List elements: " + strList);
	    }
}

Output:

Number List elements: [10]
String List elements: [Hello India]

Example 2

import java.util.*;
public class CollectionsSingletonListExample2 {
	public static void main(String[] args) {		       
		//Create an array of string objects
	      String str[] = { "One", "Two", "Three", "One", "Two", "Three", "TpointTech" };	      
	      //Create one list
	      List<String> list = new ArrayList<String>(Arrays.asList(str));	      
	      System.out.println("List value before: "+list);	      
	      //Create singleton list
	      list = Collections.singletonList("One");      
	      System.out.println("List value after: "+list);
	      }
}

Output:

List value before: [One, Two, Three, One, Two, Three, TpointTech]
List value after: [One]

Example 3

import java.util.*;
public class CollectionsSingletonListExample3 {
	public static void main(String[] args) {
		System.out.print("Enter the value: ");
		Scanner sc = new Scanner(System.in);
		int i= sc.nextInt();		
            System.out.println("Output: "+Collections.singletonList(i));
            sc.close();
	      }
}

Output:

1.	Enter the value: 55
Output: [55]
2.	Enter the value: Java
Exception in thread "main" java.util.InputMismatchException
	at java.base/java.util.Scanner.throwFor(Scanner.java:939)
	at java.base/java.util.Scanner.next(Scanner.java:1594)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
	at java.base/java.util.Scanner.nextInt(Scanner.java:2212)
at myPackage.CollectionsSingletonListExample3.main(CollectionsSingletonListExample3.java:7)

Next TopicJava Collections Class

← prev next →

We deliver comprehensive tutorials, interview question-answers, MCQs, study materials on leading programming languages and web technologies like Data Science, MEAN/MERN full stack development, Python, Java, C++, C, HTML, React, Angular, PHP and much more to support your learning and career growth.

Contact info

G-13, 2nd Floor, Sec-3, Noida, UP, 201301, India

hr@tpointtech.com

+91-9599086977

Interview Questions

Python Java Data Structure C++ C HTML JavaScript jQuery SQL Power BI

Online Compilers

C Compiler R Compiler C++ Compiler PHP Compiler Java Compiler HTML Editor Swift Compiler Python Compiler JavaScript Editor TypeScript Editor

Latest Post | Tutorials List | Privacy Policy | About Us | Contact Us

Java Collections singletonList() Method

Syntax

Parameter

Returns

Exceptions

Compatibility Version

Example 1

Example 2

Example 3

Contact info

Follow us

Top Tutorials

Interview Questions

Online Compilers

Java String Methods

Java Array Class

Java Math Methods

ArrayList Methods

Java List Methods

Java Thread Methods

Java Date Class

Java Collection Methods

Java ListIterator Class

Java NIO Tutorial

HttpURLConnection

Java Deque

Java HttpCookie Class

Java URL class

Java Vector class

Java Socket Class

Java Executors

Java Integer Class

Java IdentityHashMap

Java ArrayBlockingQueue

Java Timestamp

Java Spliterator

Java Bitset

Java Instant

Java Compiler Class

Java AtomicInteger Class

Java AtomicLong Methods

Java Authenticator

Java BigDecimal class

Big Integer Class

Java Boolean class

Java Byte Class

Java Class

Java Collections class

CopyOnWriteArrayList

LinkedBlockingDeque

Java Long class

LinkedTransferQueue

Java List

Java MulticastSocket

Java Number Class

Java Phaser Class

Java Collections singletonList() Method

Syntax

Parameter

Returns

Exceptions

Compatibility Version

Example 1

Example 2

Example 3

Related Posts

Subscribe to Tpoint Tech

Contact info

Follow us

Top Tutorials

Interview Questions

Online Compilers