One thing to note about using SingleOrDefault is that because it throws an exception if more than one match is in the list, it has to iterate through every item, where FirstOrDefault will stop searching once the first match is found. Why don't we use the 7805 for car phone chargers? What are the advantages of running a power tool on 240 V vs 120 V? rev2023.5.1.43405. Can you still use Commanders Strike if the only attack available to forego is an attack against an ally? Here is one way to rewrite your method to use LINQ: public static int GetItemIndex(string search) { List _list = new List() { "one", "two", This will give syntax error, How to set a value in one list when comparing it with other list using LINQ, How a top-ranked engineering school reimagined CS curriculum (Ep. Be aware that it only updates the first company it found with company id 1. For multiple (from c in listOfCompany where c.id == 1 select c).First( Would My Planets Blue Sun Kill Earth-Life? How to force Unity Editor/TestRunner to run at full speed when in background? I need to store the rank because the price may change Why refined oil is cheaper than cold press oil? Besides checking for it's existance with if, first. 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Generic Doubly-Linked-Lists C implementation, "Signpost" puzzle from Tatham's collection, Embedded hyperlinks in a thesis or research paper. > var boys = new List {"Harry", "Ron", "Neville"}; > boys.IndexOf ("Neville") 2 > boys [2] == "Neville" True This will help you in getting the first or default value in your LINQ List search This search will find the first or default value, which it will return. I mean, if PopulateChanges() is returning you a List<> of DateTime arrays, and you are going through all of them and setting them to DateTime.MinValue, what exactly is the code unit that you want to put in the delegate? Can my creature spell be countered if I cast a split second spell after it? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Let me try to look it up. If the null hypothesis is never really true, is there a point to using a statistical test without a priori power analysis? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, No offense, but this seems like using Linq for the sole purpose of using linq, not because it's actually solving a problem (as a matter of fact, it's created a problem), I may be wrong, but I thought there is no, How a top-ranked engineering school reimagined CS curriculum (Ep. How do they work? Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, How to overcome foreach loop for list object dynamically. c# - assign value using linq - Stack Overflow You can select multiple fields using linq Select as shown above in various examples this will return as an Anonymous Type. What positional accuracy (ie, arc seconds) is necessary to view Saturn, Uranus, beyond? If you make your expression return a value, and add something that will fully evaluate the query, such as ToList(), to the end, then it will "work", ie: That being said, ToList() has some disadvantages - mainly, it's doing a lot of extra work (to create a List) that's not needed, which adds a large cost. ), Ubuntu won't accept my choice of password. Why waste the time on it. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, Sometimes when modifying properties in a foreach loop, the changes do not remain. Did the drapes in old theatres actually say "ASBESTOS" on them? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. How can I control PNP and NPN transistors together from one pin? 565), Improving the copy in the close modal and post notices - 2023 edition, New blog post from our CEO Prashanth: Community is the future of AI. Asking for help, clarification, or responding to other answers. Not the answer you're looking for? Why is it shorter than a normal address? To learn more, see our tips on writing great answers. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. If the null hypothesis is never really true, is there a point to using a statistical test without a priori power analysis? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Where will return all items which match your criteria, so you may get an IEnumerable with one element: First will return the first item which matches your criteria: Note that FirstOrDefault() will behave the same, except it will return null for reference types, or the default value for value types, instead of throwing an exception. Nevermind, actually you can get rid of the lambdas for a few cases Great answers! What differentiates living as mere roommates from living in a marriage-like relationship? If you want the index of the element, this will do it: You can't get rid of the lambda in the first pass. UPDATE This can be simplified to be listOf Two points. Why refined oil is cheaper than cold press oil? Find centralized, trusted content and collaborate around the technologies you use most. Parabolic, suborbital and ballistic trajectories all follow elliptic paths. What is the difference between Python's list methods append and extend? Extract values from HttpContext.User.Claims, Ultrawingrid - Select row based on unique value, Concat all strings inside a List using LINQ, Using LINQ to remove elements from a List. The OP since updated the question and having it makes no more sense at all since it's true 100% of the time. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Use .ToList () in order to convert query in list that you can work with. He also rips off an arm to use as a sword. Since you haven't given any indication to what you want, here is a link to 101 LINQ samples that use all the different LINQ methods: 101 LINQ Samples. This solves the problem by resorting to nullable ints: If you want to count the number of items that match: And don't forget to check the list for null in any of these cases. Making statements based on opinion; back them up with references or personal experience. Not knowing the full extent of the data types behind the MatchA, MatchB and ToUpdate properties, it'll be difficult to give an answer which completely solves your performance issues. I don't really see how this is any different. But then, at this point, you're better off (with less typing) doing it the "clear" way: This is shorter, very clear in its intent, and very clean. If you need to add any IEnumerable collection of elements to the list you need to use AddRange. Since you want to change the properties of the elements in your enumeration, you should not be using linq or List.ForEach for that. IEnumerable vs List - What to Use? C# Set field of all items in list to same value - Stack Overflow It's an easy way to filter out nulls. rev2023.5.1.43405. There are a few ways (note that this is not a complete list). Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. When to use .First and when to use .FirstOrDefault with LINQ? Which reverse polarity protection is better and why? Thanks for contributing an answer to Code Review Stack Exchange! MathJax reference. I don't have a C# compiler here but maybe AddRange instead of Add works: Thanks for contributing an answer to Stack Overflow! Great answer. Does a password policy with a restriction of repeated characters increase security? How do I clone a list so that it doesn't change unexpectedly after assignment? c# - ToList method in Linq - Stack Overflow dont forget the return syntax it took me one hour, Very neat! class - Set the list value using linq - Stack Overflow You can remove the .ToList call. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. What's the cheapest way to buy out a sibling's share of our parents house if I have no cash and want to pay less than the appraised value? Making statements based on opinion; back them up with references or personal experience. Why did US v. Assange skip the court of appeal? Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. Update all objects in a collection using LINQ, LINQ's Distinct() on a particular property, Deserializing JSON to .NET object using Newtonsoft (or LINQ to JSON maybe? To use a linq statement to get a new List of CorrectionQuota you would do something like this: Transform the results into what you want first and then make the new List. Embedded hyperlinks in a thesis or research paper. Is a downhill scooter lighter than a downhill MTB with same performance? Has the Melford Hall manuscript poem "Whoso terms love a fire" been attributed to any poetDonne, Roe, or other? rev2023.5.1.43405. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Can you perhaps include some description of your answer instead of just posting a blob of code? Be aware that it only updates the first company it found with company id 1. For multiple (from c in listOfCompany where c.id == 1 select c).First( Why refined oil is cheaper than cold press oil? Set list property value using LINQ ForEach. Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem? Which ability is most related to insanity: Wisdom, Charisma, Constitution, or Intelligence? "Signpost" puzzle from Tatham's collection. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Not the answer you're looking for? Avoiding it would require enumerating the collection: Again, I wouldn't recommend this. Here is one way to rewrite your method to use LINQ: You can use FirstOfDefault with the Where LINQ extension to get a MessageAction class from the IEnumerable. If you really want to use linq, you can do something like this. Why is it shorter than a normal address? You should iterate your list, and modify your values like: foreach (var student in myList) { if (student.Name == "Tom") { student.Marks = 35; } } Or foreach (var student Weighted sum of two random variables ranked by first order stochastic dominance. Asking for help, clarification, or responding to other answers. using Linq would be: listOfCompany.Where(c=> c.id == 1).FirstOrDefault().Name = "Whatever Name"; Folder's list view has different sized fonts in different folders. Can you use lambda expressions and .find? Write LINQ queries in C# | Microsoft Learn By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Now, the only reason I added count was so that once 10000 items in a have been updated, the loop will stop, otherwise it will take a very long time to go thru all of the items. // Next, when I try to add vnlist to vendlist, I get an error as I cannot add this to the list I get and error saying I have some invalid arguments. If it is possible, how? For multiple. When new changes occure, then those elements get a new DateTime. Web3. Find centralized, trusted content and collaborate around the technologies you use most. Do you want the item in the list or the actual item itself (would assume the item itself). What positional accuracy (ie, arc seconds) is necessary to view Saturn, Uranus, beyond? I want to compare these lists using LINQ and if IDs from both lists are equal, I want to set WorkingID in the first list, A list.
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