sort list based on another list java sort list based on another list java

rev2023.3.3.43278. I have created a more general function, that sorts more than two lists based on another one, inspired by @Whatang's answer. I like having a list of sorted indices. You can use a Bean Comparator to sort this List however you desire. May be just the indexes of the items that the user changed. Another alternative, combining several of the answers. Asking for help, clarification, or responding to other answers. Can airtags be tracked from an iMac desktop, with no iPhone? You can create a pandas Series, using the primary list as data and the other list as index, and then just sort by the index: This is helpful when needing to order a smaller list to values in larger. Merge two lists in Java and sort them using Object property and another condition, How Intuit democratizes AI development across teams through reusability. Guide to Java 8 Collectors: groupingByConcurrent(), Java 8 - Difference Between map() and flatMap(), Java: Finding Duplicate Elements in a Stream, Java - Filter a Stream with Lambda Expressions, Guide to Java 8 Collectors: averagingDouble(), averagingLong() and averagingInt(), Make Clarity from Data - Quickly Learn Data Visualization with Python, // Constructor, getters, setters and toString(), Sorting a List of Integers with Stream.sorted(), Sorting a List of Integers in Descending Order with Stream.sorted(), Sorting a List of Strings with Stream.sorted(), Sorting Custom Objects with Stream.sorted(Comparator that maps the values of everything in listB to something that can be sorted easily, such as the index, i.e. The method returns a comparator that compares Comparable objects in the natural order. Can I tell police to wait and call a lawyer when served with a search warrant? Java Sorting Java Sorting Learn to use Collections.sort () method to sort a list of objects using some examples. You can setup history as a HashMap or separate class to make this easier. The second one is easier and faster if you're not using Pandas in your program. super T> comparator), Defining a Custom Comparator with Stream.sorted(). The solution below is simple and should fix those issues: Location of index in list2 is tracked using cur_loclist. How is an ETF fee calculated in a trade that ends in less than a year? The toList() return the collector which collects all the input elements into a list, in encounter order. Do roots of these polynomials approach the negative of the Euler-Mascheroni constant? Something like this? The solution below is simple and should fix those issues: Location of index in list2 is tracked using cur_loclist. Connect and share knowledge within a single location that is structured and easy to search. Do I need to loop through them and pass them to the compare method? To learn more, see our tips on writing great answers. As for won't work..that's right because he posted the wrong question in the title when he talked about lists. The signature of the method is: In the following example, we have used the following methods: The reverseOrder() is a method of Comparator interface which is defined in java.util package. You can do list1.addAll(list2) and then sort list1 which now contains both lists. Does Counterspell prevent from any further spells being cast on a given turn? Not the answer you're looking for? You get paid; we donate to tech nonprofits. Working on improving health and education, reducing inequality, and spurring economic growth? How do I read / convert an InputStream into a String in Java? Sorting for String values differs from Integer values. Here is my complete code to achieve this result: But, is there another way to do it? For example, when appendFirst is false below will be the output. How to match a specific column position till the end of line? Does a summoned creature play immediately after being summoned by a ready action? How can I check before my flight that the cloud separation requirements in VFR flight rules are met? How to sort one list and re-sort another list keeping same relation python? We can also pass a Comparator implementation to define the sorting rules. For Action, select Filter the list, in-place. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Sorting a list in Python using the result from sorting another list, How to rearrange one list based on a second list of indices, How to sort a list according to another list? How can this new ban on drag possibly be considered constitutional? See more examples here. Check out our offerings for compute, storage, networking, and managed databases. So you could simply have: What I am doing require to sort collection of factories and loop through all factories and sort collection of their competitors. Thanks for learning with the DigitalOcean Community. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Find centralized, trusted content and collaborate around the technologies you use most. Once you have that, define your own comparison function which compares values based on the indexes of list. More general case (sort list Y by any key instead of the default order), http://scienceoss.com/sort-one-list-by-another-list/, How Intuit democratizes AI development across teams through reusability. If the elements of the stream are not Comparable, a java.lang.ClassCastException may be thrown upon execution. To get a value from the HashMap, we use the key corresponding to that entry. The best answers are voted up and rise to the top, Not the answer you're looking for? This will sort all factories according to their price. This could be done by wrapping listA inside a custom sorted list like so: Then you can use this custom list as follows: Of course, this custom list will only be valid as long as the elements in the original list do not change. If not then just replace SortedMap indexToObj by SortedMap> indexToObjList. Once you have that, define your own comparison function which compares values based on the indexes of list. QED. I have two lists List list1 = new ArrayList(), list2 = new ArrayList(); (Not the same size), of the class Person: I want to create a new list using list1 and list2 sorted by age (descending), but I also another condition that is better explained with an example: He should, because his age is equal to Menard, Alec is from L1 and two Person from L1 can't be one after another is this kind of situation happens. Key and Value can be of different types (eg - String, Integer). Here's a simple implementation of that logic. Python. What do you mean when you say that you're unable to persist the order "on the backend"? Linear regulator thermal information missing in datasheet. It seems what you want would be to use Comparable instead, but even this isn't a good idea in this case. Surly Straggler vs. other types of steel frames. No spam ever. I am wondering if there is any easier way to do it. We can also create a custom comparator to sort the hash map according to values. Using Java 8 Streams. Speed improvement on JB Nizet's answer (from the suggestion he made himself). By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Sorting a 10000 items list 100 times improves speed 140 times (265 ms for the whole batch instead of 37 seconds) on my unit tests. Can airtags be tracked from an iMac desktop, with no iPhone? That is, the first items (from Y) are compared; and if they are the same then the second items (from X) are compared, and so on. We will also learn how to use our own Comparator implementation to sort a list of objects. Is it possible to create a concave light? So basically, I have 2 ArrayLists (listA and listB). Here if the data type of Value is String, then we sort the list using a comparator. In addition, the proposed solution won't work for the initial question as the lists X and Y contain different entries. That's right but the solutions use completely different methods which could be used for different applications. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Wed like to help. They're functional in nature, and it's worth noting that operations on a stream produce a result, but do not modify its source. A stream represents a sequence of elements and supports different kind of operations that lead to the desired result. Sorting a 10000 items list 100 times improves speed 140 times (265 ms for the whole batch instead of 37 seconds) on my I have created a more general function, that sorts more than two lists based on another one, inspired by @Whatang's answer. In this quick tutorial, we'll learn how to find items from one list based on values from another list using Java 8 Streams. To learn more about comparator, read this tutorial. Streams differ from collections in several ways; most notably in that the streams are not a data structure that stores elements. That way, I can sort any list in the same order as the source list. Use MathJax to format equations. Basically, this answer is nonsense. Overview to Sorting Stream and List on Multiple Fields Using Java 8 We perform sorting on stream and list of objects using the multiple fields using the Comparators and Comparator.thenComparing () method. How do you ensure that a red herring doesn't violate Chekhov's gun? Premium CPU-Optimized Droplets are now available. If they are already numpy arrays, then it's simply. Here is an example of how to sort a list and then make the changes in another list according to the changes exactly made to first array list. On the Data tab of the Ribbon, in the Sort & Filter group, click Advanced. (This is a very old answer!). To avoid having a very inefficient look up, you should index the items in listB and then sort listA based on it. Sign up for Infrastructure as a Newsletter. Why do academics stay as adjuncts for years rather than move around? In this case, the key extractor could be the method reference Factory::getPrice (resp. Using this method is fairly simple, so let's take a look at a couple of examples: Here, we make a List instance through the asList() method, providing a few integers and stream() them. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Assuming that the larger list contains all values in the smaller list, it can be done. Else, run a loop till the last node (i.e. If you preorder a special airline meal (e.g. You can create a pandas Series, using the primary list as data and the other list as index, and then just sort by the index: This is helpful when needing to order a smaller list to values in larger. As each pair of strings are passed in for comparison, convert them into ints using originalList.indexOf, except that if the index is -1, change the index to originalList.size () Compare the two ints. What sort of strategies would a medieval military use against a fantasy giant? Just encountered the same problem. good solution! Note: Any item not in list1 will be ignored since the algorithm will not know what's the sort order to use. Here is Whatangs answer if you want to get both sorted lists (python3). Sort a List of Integers 5 1 List<Integer> numbers = Arrays.asList(6, 2, 1, 4, 9); 2 System.out.println(numbers); 3 4 numbers.sort(Comparator.naturalOrder()); 5 System.out.println(numbers);. They store items in key, value pairs.