See the documentation for ArrayList#remove(int), as in the following syntax:
list.remove(list.size() - 1)
Here is how it's implemented. elementData does a lookup on the backing array (so it can cut it loose from the array), which should be constant time (since the JVM knows the size of an object reference and the number of entries it can calculate the offset), and numMoved is 0 for this case:
public E remove(int index) {
rangeCheck(index); // throws an exception if out of bounds
modCount++; // each time a structural change happens
// used for ConcurrentModificationExceptions
E oldValue = elementData(index);
int numMoved = size - index - 1;
if (numMoved > 0)
System.arraycopy(elementData, index+1, elementData, index,
numMoved);
elementData[--size] = null; // Let gc do its work
return oldValue;
}
Baeldung
baeldung.com › home › java › java list › removing an element from an arraylist
Removing an Element From an ArrayList | Baeldung
April 4, 2025 - Since JDK 21, a new method has joined the List family: removeLast().
Java Guides
javaguides.net › 2024 › 06 › java-arraylist-removelast-method.html
Java ArrayList removeLast() Method
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MOOC Java 03_17 RemoveLast Exercise Help Needed
Please ensure that: Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions You include any and all error messages in full - best also formatted as code block You ask clear questions You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions. If any of the above points is not met, your post can and will be removed without further warning. Code is to be formatted as code block (old reddit/markdown editor: empty line before the code, each code line indented by 4 spaces, new reddit: https://imgur.com/a/fgoFFis ) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc. Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit. Code blocks look like this: public class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above. If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures. To potential helpers Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com
3
1
March 21, 2022arraylist - Remove Last Element from a List in Java - Stack Overflow
In Java 21+, List is a sub-interface of SequencedCollection. This brings convenient new methods such as removeLast. More on stackoverflow.com
java - How to remove the last string in an array element using parameters of another method named removeLast() - Stack Overflow
Here is the question of exercise and my code: Create the method public static void removeLast(ArrayList strings) in the exercise template. The method should remove the last value in the list it rec... More on stackoverflow.com
Java* Add the removeLast method to
the ArrayList class of Section 16.4. Return the removed
element or null if the array list is empty.
ArrayList.java
/**
This is a simplified implementation of an array
list.
*/
public class ArrayList
{
private Object[] elements;
private int currentSize;
/**
Constructs an empty array list.
*/
public
Answer to Java* Add the removeLast method to the ArrayList More on chegg.com
1
April 5, 2022 Top answer 1 of 2
98
See the documentation for ArrayList#remove(int), as in the following syntax:
list.remove(list.size() - 1)
Here is how it's implemented. elementData does a lookup on the backing array (so it can cut it loose from the array), which should be constant time (since the JVM knows the size of an object reference and the number of entries it can calculate the offset), and numMoved is 0 for this case:
public E remove(int index) {
rangeCheck(index); // throws an exception if out of bounds
modCount++; // each time a structural change happens
// used for ConcurrentModificationExceptions
E oldValue = elementData(index);
int numMoved = size - index - 1;
if (numMoved > 0)
System.arraycopy(elementData, index+1, elementData, index,
numMoved);
elementData[--size] = null; // Let gc do its work
return oldValue;
}
2 of 2
10
Since Java 21, simply using List.removeLast, for example:
List<Integer> list = new ArrayList<>(List.of(1, 2, 3));
System.out.println(list.removeLast()); // 3 - removes and returns the last element
Note: if the list is not empty, the implementation of List.removeLast returns the result of calling remove(size() - 1). Otherwise, it throws NoSuchElementException.
The time complexity of removing the last element from ArrayList is O(1) - it is just decrementing the size of the list by 1 under the hood.
Ramesh Fadatare
rameshfadatare.com › home › java arraylist removelast() method (introduced in java 21)
Java ArrayList removeLast() Method (introduced in Java 21)
June 12, 2024 - The removeLast method can be used to remove the last element of the ArrayList.
Reddit
reddit.com › r/learnjava › mooc java 03_17 removelast exercise help needed
r/learnjava on Reddit: MOOC Java 03_17 RemoveLast Exercise Help Needed
March 21, 2022 -
So I'm just starting the Mooc java course and i'm not sure how to get past this exercise.
Here's my code:
import java.util.ArrayList;
public class RemoveLast {
public static void main(String[] args) {
}
public static void remove (ArrayList<String> list) {
if (!list.isEmpty()) {
int last = list.size() - 1;
list.remove(last);
}
}
}
When I start using the method nothing seems to be wrong, but when I submit it, the fail message tells me "the removeLast method should not cause an exception. Make sure the method doesn't do anything to an empty list."
Thank you :)
Top answer 1 of 2
1
Please ensure that: Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions You include any and all error messages in full - best also formatted as code block You ask clear questions You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions. If any of the above points is not met, your post can and will be removed without further warning. Code is to be formatted as code block (old reddit/markdown editor: empty line before the code, each code line indented by 4 spaces, new reddit: https://imgur.com/a/fgoFFis ) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc. Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit. Code blocks look like this: public class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above. If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures. To potential helpers Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.
2 of 2
1
I believe the method is correct. I guess you should change the name of static method to removeLast or something for letting the text part know it is the method needs to call. If it didn’t work, then I don’t know why.
Baeldung
baeldung.com › home › java › java collections › guide to the java arraylist
Guide to the Java ArrayList | Baeldung
December 14, 2024 - @Test public void givenSequenc... arrayList.removeFirst()); } Similarly, to remove the last element in an existing collection, we call the instance method removeLast()....
GitHub
github.com › jumpalottahigh › JavaChallenge-MOOC-course › blob › master › week3-062.RemoveLast › src › RemoveLast.java
JavaChallenge-MOOC-course/week3-062.RemoveLast/src/RemoveLast.java at master · jumpalottahigh/JavaChallenge-MOOC-course
ArrayList<String> persons = new ArrayList<String>(); persons.add("Pekka"); persons.add("James"); persons.add("Liz"); persons.add("Brian"); · System.out.println("Persons:"); System.out.println(persons); · // sort the persons · Collections.sort(persons); · // and remove the last · removeLast(persons); ·
Author: jumpalottahigh
Top answer 1 of 2
5
tl;dr
pathToFile.getParent()
Path#getParent
No need to resort to crude string manipulation. Java NIO abstracts us away from the platform-specific details.
Call Path#getParent to get another path object while dropping the last element of the original.
Path pathToFile = Paths.get( "SomeFolder" , "SomeFile" ) ;
Path pathToFolder = pathToFile.getParent() ;
List#removeLast
By the way, to answer the title of your Question…
In Java 21+, List is a sub-interface of SequencedCollection. This brings convenient new methods such as removeLast.
myList.removeLast() ;
2 of 2
1
Actually, you might be getting the UnsupportedOperationException, this is happening because you have used the Arrays.asList method, by using which the list cannot be modified i.e. no elements can be added or removed from the path list.
So, to perform your desired operation, you can use the below code.
String[] pathArray = Paths.get("").toAbsolutePath().toString().split("\\\\");
List<String> path = new ArrayList<>();
Collections.addAll(path, pathArray);
System.out.println(path);
int removeJavaFile = path.size() - 1;
path.remove(removeJavaFile);
System.out.println("Path: "+path);
String filePath = path.stream().map(n -> String.valueOf(n)).collect(Collectors.joining("\\\\"));
System.out.println(filePath);
Here, first you get the pathArray and then add those array elements into a list which can be modified which makes you remove the last element from the list.
Stack Overflow
stackoverflow.com › questions › 73720564 › how-to-remove-the-last-string-in-an-array-element-using-parameters-of-another-me
java - How to remove the last string in an array element using parameters of another method named removeLast() - Stack Overflow
But, you are being passed (a copy of) the reference to the ArrayList to be modified. So, when you change the contents of the list, it is changed in the calling method. ... Save this answer. ... Show activity on this post. "If the list is empty, the method does nothing" --> Check if the list is empty or not, if empty just return nothing , else delete last element(as per your requirement) ... Copypublic static void removeLast(ArrayList<String> strings) { if( (strings.isEmpty())) { return; } else { strings.remove(strings.size()-1); } }
GeeksforGeeks
geeksforgeeks.org › java › removing-last-element-from-arraylist-in-java
Removing last element from ArrayList in Java - GeeksforGeeks
July 12, 2025 - We can use the remove() method of ArrayList container in Java to remove the last element.
GeeksforGeeks
geeksforgeeks.org › java › linkedlist-removelast-method-in-java
LinkedList removeLast() Method in Java - GeeksforGeeks
July 11, 2025 - Exception: If the list is empty, calling removeLast() will throw a NoSuchElementException.
TutorialsPoint
tutorialspoint.com › java › util › arraydeque_removelast.htm
Java ArrayDeque removeLast() Method with Examples
Find the perfect tutorial for your learning journey · The Java ArrayDeque removeLast() method retrieves and removes the last element of this deque. This operation modifies the ArrayDeque instance
W3Schools
w3schools.com › java › ref_arraylist_remove.asp
Java ArrayList remove() Method
The remove() method removes an item from the list, either by position or by value. If a position is specified then this method returns the removed item.
Level Up Lunch
leveluplunch.com › java › examples › remove-last-element-arraylist
Remove last element in arraylist | Level Up Lunch
January 31, 2015 - @Test public void drop_last_element_java() { List<String> lastElementRemoved = new ArrayList<String>(); lastElementRemoved.add("one"); lastElementRemoved.add("two"); lastElementRemoved.add("three"); lastElementRemoved.remove(lastElementRemoved.size() - 1); assertEquals(2, lastElementRemoved.size()); }
Xenovation
xenovation.com › home › blog › java › how to remove the last element from list in java?
How to remove the last element from List in Java? (ArrayList, LinkedList, Vector)
June 24, 2020 - import java.util.ArrayList; import java.util.List; public class RemoveLastElementFromList { public static void main(String[] args) { List lList = new ArrayList<>(); RemoveLastElementFromList lMyClass = new RemoveLastElementFromList(); lMyClass.addTestData(lList); lMyClass.removeLastElement(lList); } public void removeLastElement(List<?> pList) { // get the index of the last entry from the list int lLastIndex = -1; if (pList.isEmpty()) { // nothing to remove } else { lLastIndex = pList.size() - 1; // if you do not need the last element anymore pList.remove(lLastIndex); } } public void addTestData(List pList) { pList.add("first"); pList.add("second"); pList.add("third"); pList.add("fourth"); } }
Top answer 1 of 7
87
It should be:
ClientThread hey = clients.get(clients.size() - 1);
clients.remove(hey);
Or you can do
clients.remove(clients.size() - 1);
The minus ones are because size() returns the number of elements, but the ArrayList's first element's index is 0 and not 1.
2 of 7
8
The compiler complains that you are trying something of a list of ClientThread objects to a String. Either change the type of hey to ClientThread or clients to List<String>.
In addition: Valid indices for lists are from 0 to size()-1.
So you probably want to write
String hey = clients.get(clients.size()-1);
Reactgo
reactgo.com › home › how to remove the last element of an arraylist in java
How to remove the last element of an ArrayList in Java | Reactgo
December 24, 2022 - To remove the last element of a ArrayList, we can use the list.remove() method by passing its index list.size()-1 as an argument to it.
CodeGym
codegym.cc › java blog › java collections › how to remove an element from arraylist in java?
How to remove an element from ArrayList in Java | CodeGym
December 10, 2024 - The iterator is smarter than it may appear: remove() removes the last element returned by the iterator. As you can see, it did just what we wanted it to do :) In principle, this is everything you need to know about removing elements from an ...
W3Schools
w3schools.com › java › ref_linkedlist_removelast.asp
Java LinkedList removeLast() Method
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