kotlin replace list with another list

Connect and share knowledge within a single location that is structured and easy to search. How to vet a potential financial advisor to avoid being scammed? For building maps with collection elements as values, there is the function associateBy(). And of course it depends on your use-case - the slicing approach for example uses more intermediate lists than the mapping approach, and that might be a concern in addition to raw speed. Replace element in ArrayList of objects [Kotlin]. It applies the given lambda function to each subsequent element and returns the list of the lambda results. } How to replace item in list based off name in kotlin? Replacing rusty trunk dampener - one or both? When called on a collection or an array with another collection (or array) as an argument, zip() returns the List of Pair objects. parse and replace a list of object in kotlin - Stack Overflow Best way to "replace" an element of an immutable list getOrNull() returns null as the default value. Why do some fonts alternate the vertical placement of numerical glyphs in relation to baseline? To build a custom string representation, you can specify its parameters in function arguments separator, prefix, and postfix. val numbers = listOf("one", "two", "three", "four") val twoAnimals = listOf("fox", "bear") Techniques for Spring Developers". return FullName(nameParts[0], nameParts[1]) Using replaceAll () function The standard solution to replace values in a list is using the replaceAll () function. Kotlin String replace including delimiter. //sampleStart To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 1.0 fun String.replace( oldValue: String, newValue: String, ignoreCase: Boolean = false ): String (Common source) (JVM source) (JS source) (Native source) Returns a new string obtained by replacing all occurrences of the oldValue substring in this string with the specified newValue string. Question from IQ test involving patterns of white, yellow, red, and grey squares, A "simpler" description of the automorphism group of the Lamplighter group. Asking for help, clarification, or responding to other answers. Modifying Kotlin Lists In-Place | Baeldung on Kotlin We can add elements to or remove elements from this Mutable List. Does a Wand of Secrets still point to a revealed secret or sprung trap? with the result of the given function transform that takes MatchResult and returns a string to be used as a Why speed of light is considered to be the fastest? A mutable list allows us to append and modify elements. Kotlin zip () . Conclusions from title-drafting and question-content assistance experiments string arraylist delete an element and again put the element at the same position. By using this site, you agree to the use of cookies, our policies, copyright terms and other conditions. They return the first and the last position of an element equal to the given argument in the list. If the list size is less than the specified index, an exception is thrown. //sampleStart }, fun main() { //sampleEnd This returned value is used as the new element for the list. KotlinListOf.kt Since we want to do an in-place modification, were going to use mutable lists in this article. Another function flatMap() provides a flexible way to process nested collections. numbers.sort() How to compare two lists and insert values based on one into the other by a property in kotlin? For example: To an outside class, this List is read-only, but not immutable. asReversed() called on a mutable list returns another mutable list which is a reversed view of the original list. fun parseFullName(fullName: String): FullName { Lists support all common operations for element retrieval: elementAt(), first(), last(), and others listed in Retrieve single elements. println("Sort into ascending by length: $numbers") Conclusions from title-drafting and question-content assistance experiments Update (or Replace) item(s) in immutable collection in Scala. It is not permissible to modify a list while iterating over it; otherwise, ConcurrentModificationException will be thrown. As a result, flatMap() returns a single list of its return values on all the elements. fill() simply replaces all the collection elements with the specified value. //sampleEnd In this tutorial, we will go through basic topics of a mutable list like creating a mutable list, adding elements to a mutable list and removing elements from a mutable list. List - Kotlin Programming Language Kotlin List & Mutable List tutorial with examples - BezKoder How do I replace multiple characters in a String? The MutableListIterator has the typical hasNext() and next() methods to loop over the list but it also contains a set method. println("Shuffle: $numbers") Equivariant perverse sheaves and orbit stratification, Tikz Calendar - how to pass argument with '\def'. println(colors zip animals) What is the "salvation ready to be revealed in the last time"? println(numbers.getOrElse(5, {it})) // 5 println("Sort by Comparator: $numbers") The second list contains the second elements. When you have a List of Pairs, you can do the reverse transformation unzipping that builds two lists from these pairs: The first list contains the first elements of each Pair in the original list. First split the string to a list of its words and then map each word if it exists in list a to the corresponding word in list b. China produces around 60% of the world's germanium, according to European industry association Critical Raw Materials Alliance (CRMA), with the rest coming from Canada, Finland, Russia and the . println(colors.binarySearch("RED", String.CASE_INSENSITIVE_ORDER)) // 3 1.0 interface MutableList<E> : List<E>, MutableCollection<E> (source) A generic ordered collection of elements that supports adding and removing elements. Thanks for contributing an answer to Stack Overflow! //sampleEnd println(numbers.binarySearch("two")) // 3 Now Lane Kiffin will try to replace Demond Williams Jr. with another signal caller. }, fun main() { }, fun main() { Instead, it takes a comparison function mapping elements to Int values and searches for the element where the function returns zero. These functions build new collections from existing ones based on the transformation rules provided. How to remove item and replace it with a new one at the same place in ArrayList? println(numbers) If you need to retrieve the collection content in a readable format, use functions that transform the collections to strings: joinToString() and joinTo(). //sampleStart First, you're missing comma after properties in your data classes, so it should be: As for second problem, there're probably number of ways to do that, but I've only corrected your idea: Instead of assigning values to variables, you can name parameter for forEach and use it in rest of the loop. //sampleStart //sampleStart var list: ArrayList = arrayListOf("one", "two", "three"). It will probably also change the order of the items in the list. Did the US government claim that it has the right to control "cognitive infrastructure", i.e. //sampleStart If so, we return 0, otherwise, we return the element without changes. Enter your email address to subscribe to new posts. Not the answer you're looking for? //sampleStart //sampleStart Improve The Performance Of Multiple Date Range Predicates, Sum of a range of a sum of a range of a sum of a range of a sum of a range of a sum of, Google Chrome Not Displaying Websites Correctly, Simplify exponential expression inside Function. So, having a list sorted ascending according to this order, we use binarySearch() to find the index of the specified Product. Can Loss by Checkmate be Avoided by Invoking the 50-Move Rule Immediately After the 100th Half-Move? What is the purpose of putting the last scene first? initial: R, operation: (index: Int, acc: R, T) -> R. Find centralized, trusted content and collaborate around the technologies you use most. Map val numbers = mutableListOf("one", "two", "three", "four") To subscribe to this RSS feed, copy and paste this URL into your RSS reader. println(numbers.associateWith { it.length }) }, fun main() { Not the answer you're looking for? Here's a playground example - definitely not the best place to do benchmarking, but it can be instructive as a general ballpark if you run things a few times: Broadly speaking, mapping takes 60-100% more time than the slice-and-combine approach. This website uses cookies. IQ question involving patterns of lines joined together. To make "I am an amateur" to "You are an amateur". //sampleStart Product("DotTrace", 129.0), . StringContainer(listOf("seven", "eight")) numbers[1] = "two" 588), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned. kotlin.text.Regex.Companion.escapeReplacement. [Person(name=James, age=18, cat=Adult), Person(name=Mary, age=20, cat=Adult), Person(name=Jennifer, age=25, cat=Adult)]. //sampleEnd You can call it on a collection of collections, for example, a List of Sets. println(numbers.get(0)) Custom comparators are also handy when a list uses an order different from natural one, for example, a case-insensitive order for String elements. Question from IQ test involving patterns of white, yellow, red, and grey squares. To learn more, see our tips on writing great answers. Did you consider using a map instead? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Can Loss by Checkmate be Avoided by Invoking the 50-Move Rule Immediately After the 100th Half-Move? How can i do that? Does it cost an action? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Kotlin - Collections (List, Map, Set) 22 The Kotlin lists have the plus operator overloaded in kotlin-stdlib, so you can add an item to a list: val values = listOf (1, 2, 3, 4, 5, 6) return values + 7 There's also an overload that adds another list: val values = listOf (1, 2, 3, 4, 5, 6) return listOf (-1, 0) + values + listOf (7, 8) Are packaged masalas to be used in combination with or instead of other spices? Let's say you want to replace the word "am", your regex will be "\bam\b". }, fun main() { val numbers = mutableListOf(1, 2, 3, 4) How to replace an Element at Specific Index in Kotlin List? - Tutorial Kart To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Use Lists in Kotlin | Android Developers Read-only lists are created with listOf and mutable lists with mutableListOf . Product("ReSharper", 149.0)) The order of results is the same as the original order of elements. //sampleEnd, fun main() { Conclusions from title-drafting and question-content assistance experiments How to replace all occurrences of a substring in Kotlin. kotlin - How to remove item and replace it with a new one at the same Let's have a look at an example: Here's a list of Product instances that aren't Comparable and a Comparator that defines the order: product p1 precedes product p2 if p1's price is less than p2's price. 2. Find centralized, trusted content and collaborate around the technologies you use most. Find centralized, trusted content and collaborate around the technologies you use most. Working With Lists in Kotlin | Baeldung on Kotlin To only modify the first matching object, use the find() function. //sampleEnd Is a thumbs-up emoji considered as legally binding agreement in the United States? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Finally rejoin the string: I assume there is no punctuation, all whitespaces are spaces and so on. Does attorney client privilege apply when lawyers are fraudulent about credentials? Thanks for contributing an answer to Stack Overflow! How to remove item and replace it with a new one at the same place in ArrayList? Why does Isildur claim to have defeated Sauron when Gil-galad and Elendil did it? }, fun main() { //sampleStart println(numbers.map { it * 3 }) If two elements' keys are equal, only the last one remains in the map. What is specific for lists is index access to the elements, so the simplest way to read an element is retrieving it by index. This way, we avoid modifying the MutableList source code and can include it in selected places. //sampleStart associateBy() can also be called with a value transformation function. val numbers = mutableListOf("one", "five", "six") thanks for pointing this out! Zach Berry about 5 hours. Do NOT follow this link or you will be banned from the site. I use forEach as filter returns a List. 588), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned. println("Sort into ascending: $numbers") Product("AppCode", 99.0), How to remove and replace an item in an array list in Java? Why do we say "narrow artificial intelligence" but "artificial general intelligence"? }, fun main() { Is a thumbs-up emoji considered as legally binding agreement in the United States? //sampleStart By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. }, fun main() { How to create a list with an attribute taken from objects of a list in kotlin, create objects based on elements of a list. numbers.joinTo(listString) }, fun main() { The method expects a mutator parameter, which is the function that will be applied to every element in the list. }, fun main() { Asking for help, clarification, or responding to other answers. Thank you for answer. Association transformations allow building maps from the collection elements and certain values associated with them. This article explores different ways to conditionally remove elements from a mutable list in Kotlin. //sampleStart Making statements based on opinion; back them up with references or personal experience. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, this is the most descriptive answer and thank you very much @moira, parse and replace a list of object in kotlin, Exploring the infrastructure and code behind modern edge functions, Jamstack is evolving toward a composable web (Ep. println("Reverse: $numbers") To apply a transformation that additionally uses the element index as an argument, use mapIndexed(). I've updated the code. //sampleEnd Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Does attorney client privilege apply when lawyers are fraudulent about credentials? println(numbers.mapIndexed { idx, value -> value * idx }) Syntax: ArrayList<Integer> gfg=new ArrayList<> (); ArrayList<Integer> gfg2=gfg; Below is the implementation of the above problem statement. }, fun main() { Kotlin: How apply all list elements to the object? Conditionally remove elements from a list in Kotlin //sampleEnd fun main() { Modifying point density depending on Z position when using distribute points on faces. 588), Starting the Prompt Design Site: A New Home in our Stack Exchange Neighborhood, Temporary policy: Generative AI (e.g., ChatGPT) is banned. Can Loss by Checkmate be Avoided by Invoking the 50-Move Rule Immediately After the 100th Half-Move? val numbers = mutableListOf(1, 2, 3, 4, 3) If we combine these, it effectively sets the name of the first element which matches this condition. @Tenfour04 sorry, my previous logic was wrong. Is it legal to cross an internal Schengen border without passport for a day visit. You could do this by, for example, slicing the list around the element you want to change, and building your final list from those parts: This way you get to take advantage of any efficiency from the underlying list copy methods, versus map which has to "transform" each item even if it ends up passing through the original. }, fun main() { Why is type reinterpretation considered highly problematic in many programming languages? By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. The first one iterates the list up to 2 times, but the second iteration breaks early once it finds the item. Is this a sound plan for rewiring a 1920s house? 1. it's not working but I do not see how to make it easier to work. Does a Wand of Secrets still point to a revealed secret or sprung trap? Is there an equation similar to square root, but faster for a computer to compute? This might be useful if the operations were performing in the list depend on previous elements of the list. The method will receive a function as a parameter, and well apply this function to every element in the list. Is every finite poset a subset of a finite complemented distributive lattice? Is every finite poset a subset of a finite complemented distributive lattice? 2 Answers Sorted by: 2 First of all: you're not assigning assignedTo, you're assigning name . And slicing takes 2-3x longer than just a straight mutable copy and update. If the transformation produces null on certain elements, you can filter out the nulls from the result collection by calling the mapNotNull() function instead of map(), or mapIndexedNotNull() instead of mapIndexed(). zip() can also be called in the infix form a zip b. It replaces each element of the list with the result of applying the specified operator to it. Product("DotTrace", 129.0), Additionally, your constructor parameters to the data class are normal parameters, and as such, need commas between them! //sampleEnd in the predicate passed to find, which should only return a Boolean value to filter elements, and should probably not have any side effects, those should be done later with a call to i.e. Is it okay to change the key signature in the middle of a bar? For mutable lists, the standard library offers similar extension functions that perform the same ordering operations in place. To search an element in a sorted list, call the binarySearch() function passing the value as an argument. Asking for help, clarification, or responding to other answers. To learn more, see our tips on writing great answers. Spring. println(numbers[0]) StringContainer(listOf("one", "two", "three")),
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kotlin replace list with another list 2023