How do I generate random integers within a specific range in Java? You should instead use [x for (y,x) in sorted(zip(Y,X), key=lambda pair: pair[0])]. We can sort the entries in a HashMap according to keys as well as values. The common non-linear data structure known as a tree. The solution below is the most efficient in this case: Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. A stream represents a sequence of elements and supports different kind of operations that lead to the desired result. One with the specific order the lists should be in (listB) and the other has the list of items (listA). In Java there are set of classes which can be useful to sort lists or arrays. You return. L1-50 first, L2-50 next, then, L2-45, L2-42, L1-40 and L1-30. I think most of the solutions above will not work if the 2 lists are of different sizes or contain different items. I see where you are going with it, but you need to rethink what you were going for and edit this answer. If we talk about the working of this method, then the method works on ASCII values. See more examples here. The returned comparable is serializable. Like Tim Herold wrote, if the object references should be the same, you can just copy listB to listA, either: Or this if you don't want to change the List that listA refers to: If the references are not the same but there is some equivalence relationship between objects in listA and listB, you could sort listA using a custom Comparator that finds the object in listB and uses its index in listB as the sort key. How can I pair socks from a pile efficiently? They store items in key, value pairs. Whereas, Integer values are directly sorted using Collection.sort(). What is the shortest way of sorting X using values from Y to get the following output? Replacing broken pins/legs on a DIP IC package. @RichieV I recommend using Quicksort or an in-place merge sort implementation. No spam ever. This is a very nice way to sort the list, and to clarify, calling with appendFirst=true will sort the list as [d, c, e, a, b], @boxed__l: It will sort the elements contained in both lists in the same order and add at the end the elements only contained in A. It is defined in Stream interface which is present in java.util package. Check out our offerings for compute, storage, networking, and managed databases. So basically, I have 2 ArrayLists (listA and listB). This gives you more direct control over how to sort the input, so you can get sorting stability by simply stating the specific key to sort by. To get a value from the HashMap, we use the key corresponding to that entry. 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? Thanks for learning with the DigitalOcean Community. My lists are long enough to make the solutions with time complexity of N^2 unusable. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. All the elements in the list must implement Comparable interface, otherwise IllegalArgumentException is thrown. Is it possible to rotate a window 90 degrees if it has the same length and width? I suspect the easiest way to do this will be by writing a custom implementation of java.util.Comparator which can be used in a call to Collections.sort(). 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. Here we will learn how to sort a list of Objects in Java. People will search this post looking to sort lists not dictionaries. All rights reserved. This can create unstable outputs unless you include the original list indices for the lexicographic ordering to keep duplicates in their original order. Just encountered the same problem. Now it produces an iterable object. 2. Assuming that the larger list contains all values in the smaller list, it can be done. Rather than using a list to get values from the map, well be using LinkedHashMap to create the sorted hashmap directly. Using Kolmogorov complexity to measure difficulty of problems? - Hatefiend We can use Collections.sort() method to sort a list in the natural ascending order. In each iteration, follow the following step . If you're using Java 8, you can even get rid of the above FactoryPriceComparator and use the built-in Comparator.comparingDouble(keyExtractor), which creates a comparator comparing the double values returned by the key extractor. If you try your proposed code, it would give something like this: Person{name=Giant L2, age=100} Person{name=Derp L1, age=50} Person{name=John L2, age=50} Person{name=Menard L1, age=44} Person{name=Lili L1, age=44} Person{name=Lili L2, age=44} Person{name=Menard L2, age=44} Person{name=Bob L1, age=22} Person{name=Alec L1, age=21} Person{name=Herp L1, age=21} Person{name=Alec L2, age=21} Person{name=Herp L2, age=21} Person{name=Alice L1, age=12} Person{name=Little L2, age=5} And it's not what I'm looking for. Is there a single-word adjective for "having exceptionally strong moral principles"? Sometimes, you might want to switch this up and sort in descending order. T: comparable type of element to be compared. I have a list of factories. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. On the other hand, a Comparator is a class that is comparing 2 objects of the same type (it does not compare this with another object). Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. How To Install Grails on an Ubuntu 12.04 VPS, Simple and reliable cloud website hosting, New! HashMap entries are sorted according to String value. Speed improvement on JB Nizet's answer (from the suggestion he made himself). The source of these elements is usually a Collection or an Array, from which data is provided to the stream. Both of these variations are instance methods, which require an object of its class to be created before it can be used: This methods returns a stream consisting of the elements of the stream, sorted according to natural order - the ordering provided by the JVM. - the incident has nothing to do with me; can I use this this way? A example will show this. We can sort a list in natural ordering where the list elements must implement Comparable interface. Though it might not be obvious, this is exactly equivalent to, This is correct, but I'll add the note that if you're trying to sort multiple arrays by the same array, this won't neccessarily work as expected, since the key that is being used to sort is (y,x), not just y. 2023 DigitalOcean, LLC. If you have any suggestions for improvements, please let us know by clicking the report an issue button at the bottom of the tutorial. then the question should be 'How to sort a dictionary? Whats the grammar of "For those whose stories they are"? String values require a comparator for sorting. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Find centralized, trusted content and collaborate around the technologies you use most. Edit: Fixed this line return this.left.compareTo(o.left);. Filtering a Java Collection by a List | Baeldung This tutorial covered sorting of HashMap according to Value. Any suggestions? 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. I mean swapItems(), removeItem(), addItem(), setItem() ?? Does this require that the values in X are unqiue? That's easily managed with an index list: Since the decorate-sort-undecorate approach described by Whatang is a little simpler and works in all cases, it's probably better most of the time. The basic strategy is to get the values from the HashMap in a list and sort the list. Linear regulator thermal information missing in datasheet. good solution! Learn more about Stack Overflow the company, and our products. There are plenty of ways to achieve this. [Solved] Sorting a list based on another list's values - Java This method will also work when both lists are not identical: Problem : sorting a list of Pojo on the basis of one of the field's all possible values present in another list. What am I doing wrong here in the PlotLegends specification? This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. Using Kolmogorov complexity to measure difficulty of problems? How to sort one list and re-sort another list keeping same relation python? Another alternative, combining several of the answers. Let's look at the code. What happens if you have in List1, 50, 40 30 , and in List2 50 45 42? Not the answer you're looking for? For more information on how to set\use the key parameter as well as the sorted function in general, take a look at this. The Collections (Java Doc) class (part of the Java Collection Framework) provides a list of static methods which we can use when working with collections such as list, set and the like. If the elements of the stream are not Comparable, a java.lang.ClassCastException may be thrown upon execution. Basically, this answer is nonsense. Another alternative, combining several of the answers. Making statements based on opinion; back them up with references or personal experience. Learn the landscape of Data Visualization tools in Python - work with Seaborn, Plotly, and Bokeh, and excel in Matplotlib! Now it produces an iterable object. The preferred way to add something to SortedDependingList is by already knowing the index of an element and adding it by calling sortedList.addByIndex(index); If the two lists are guaranteed to contain the same elements, just in a different order, you can use List