I think you try to add a complete list instead of a single CheckItems instance. Why did DOS-based Windows require HIMEM.SYS to boot? create enumerables over existing collections. Certainly, foreach is the right way. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, How to use LINQ to select object with minimum or maximum property value, LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria. How can I control PNP and NPN transistors together from one pin? rev2023.5.1.43405. I pass a List a using ref, along with another List b. I need to cycle thru List b, which contains around 200,000 items, and for each item in b, it it matches criteria in a, which contains 100,000 or more items, and update it. When do you use in the accusative case? Not the answer you're looking for? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Connect and share knowledge within a single location that is structured and easy to search. //using linq list = Students.Where (s => s.Name == "ABC").ToList (); //traditional way foreach (var student in Students) { if (student.Name == "ABC") list.Add By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. How to call asynchronous method from synchronous method in C#? What were the most popular text editors for MS-DOS in the 1980s? Is a downhill scooter lighter than a downhill MTB with same performance? This appears to be a response to another answer rather than an answer to the question. > 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. If you need to add any IEnumerable collection of elements to the list you need to use AddRange. Making statements based on opinion; back them up with references or personal experience. A boy can regenerate, so demons eat him for years. It only takes a minute to sign up. using Linq would be: listOfCompany.Where(c=> c.id == 1).FirstOrDefault().Name = "Whatever Name"; UPDATE This can be simplified to be listOf rev2023.5.1.43405. The code will look something like this. WebIf you really want to use linq, you can do something like this li= (from tl in li select new Myclass { name = tl.name, age = (tl.name == "di" ? Please read, Updating items of one List that match another List, How a top-ranked engineering school reimagined CS curriculum (Ep. Use LINQ to get items in one List<>, that are not in another List<>. rev2023.5.1.43405. Asking for help, clarification, or responding to other answers. (from c in listOfCompany where c.id == 1 select c).First ().Name = "Whatever Name"; For Multiple updates. I am using below linq query to set value of SecKey, but I still see the old value in list studentData, below id the sample I am Why did US v. Assange skip the court of appeal? Making statements based on opinion; back them up with references or personal experience. When do you use in the accusative case? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, That's great. If you want to avoid this anonymous type here is the 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. How to force Unity Editor/TestRunner to run at full speed when in background? 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? What differentiates living as mere roommates from living in a marriage-like relationship? I would externalize that part into a function to make it more manageable. You really shouldn't use LINQ to perform side effects. Which reverse polarity protection is better and why? This assumes that there are only 3 types of name. It doesn't work. First, there's no real need to use. Here I have a simple example to find an item in a list of strings. As sircodesalot mentioned, you can't use linq to do something like that. Adding EV Charger (100A) in secondary panel (100A) fed off main (200A), Folder's list view has different sized fonts in different folders. Where does the version of Hamapil that is different from the Gemara come from? 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. Which ability is most related to insanity: Wisdom, Charisma, Constitution, or Intelligence? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Thanks for contributing an answer to Stack Overflow! Find centralized, trusted content and collaborate around the technologies you use most. How do I split a list into equally-sized chunks? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. So any LINQ way to search like "from .. in where select", Nah, sorry. Even if there is a solution out there, I'm not sure I'd use Linq for something like this. { In my application I have a list of items I need to sort by price and set a rank/position index for each item. Is "I didn't think it was serious" usually a good defence against "duty to rescue"? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. If we had a video livestream of a clock being sent to Mars, what would we see? Identify blue/translucent jelly-like animal on beach. Besides, the LINQ equivalent probably wouldn't be any less verbose than my example above. Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem? Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. When changes are cleared, I need to reset the times to MinValue. 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: Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Connect and share knowledge within a single location that is structured and easy to search. While you can use a ForEach extension method, if you want to use just the framework you can do collection.Select (c => {c.PropertyToSet = value; return Not the answer you're looking for? Use a combination of query syntax and method Whenever I wish to access my margins values, for instance, I address my dictionary: So, depending on what you're doing, a dictionary can be useful. Short story about swapping bodies as a job; the person who hires the main character misuses his body. (from c in listOfCompany where c.id == 1 select c).First ().Name = "Whatever Name"; For Multiple updates. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. The only difference between them is that the .First method will throw an exception if there is no such object in the collection when the second one returns the 10 : (tl.name == "marks" ? (Only assignment, call, increment, decrement, await, and new object expressions can be used as a statement). correctionQoutas is a custom object that has four properties. Normally I use a for loop or anonymous delegate to do it like this: LINQ is new for me. If it is possible, how? Can I use the spell Immovable Object to create a castle which floats above the clouds? It will, except for one small detail the numbering will start from 2. Would My Planets Blue Sun Kill Earth-Life? You can't modify a collection while you're iterating it. I don't have a C# compiler here but maybe AddRange instead of Add works: 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? Parabolic, suborbital and ballistic trajectories all follow elliptic paths. For multiple. Nevermind, actually you can get rid of the lambdas for a few cases Great answers! Or use (list ?? it will be discarded but, how will you replace older list values? Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem? By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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? 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. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Asking for help, clarification, or responding to other answers. All values are updated in one line of code and you browse the List only ONE time. This article shows the three ways in which you can write a LINQ query in C#: Use query syntax. For Starship, using B9 and later, how will separation work if the Hydrualic Power Units are no longer needed for the TVC System? Was Aristarchus the first to propose heliocentrism? The best answers are voted up and rise to the top, Not the answer you're looking for? What is Wario dropping at the end of Super Mario Land 2 and why? In both cases , the update is not done with Linq :). Asking for help, clarification, or responding to other answers. Find centralized, trusted content and collaborate around the technologies you use most. However, one potential optimization could be realized in your foreach line as such: This would limit the set brought back to only those members that actually need their ToUpdate set rather than just setting them whether they need to or not. I don't really see how this is any different. One other point I should mention is that the Select method does a projection of some specific information to return to an IEnumerable. Double StartTime, Double EndTime, Double Value and string Id. What positional accuracy (ie, arc seconds) is necessary to view Saturn, Uranus, beyond? For multiple. Note that this will throw if the item doesn't exist. Should I re-do this cinched PEX connection? Use LINQ to get items in one List<>, that are not in another List<>, Simple deform modifier is deforming my object. 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. When new changes occure, then those elements get a new DateTime. If the null hypothesis is never really true, is there a point to using a statistical test without a priori power analysis? Your first example is actually the correct method. Why does Acts not mention the deaths of Peter and Paul? If x.Value has decimals, I want to change that value to take just the first decimal woithout rounding it. When do you use in the accusative case? This new list is then discarded. If you simply need to get the elements that are of a certain type, you can do this: That would give the subset that are MyQuota or are directly assignable to that type. //d Why are players required to record the moves in World Championship Classical games? If we had a video livestream of a clock being sent to Mars, what would we see? Weighted sum of two random variables ranked by first order stochastic dominance. At this point, the Select option is far uglier, more typing, etc. User without create permission can create a custom object from Managed package using Custom Rest API. But,in my case, I must repeat the foreach in many collections, and I didn't want to repeat the loop. One more way to check the existence of an element in a List: You want to search an object in object list. Google "LINQ side effects" for more information. Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. It's an easy way to filter out nulls. Identify blue/translucent jelly-like animal on beach. If you had a more generic collection IEnumerable, you can use Select in Linq to build a projection where property will be set as desired (original collection will be left untouched!): listOfRequestAssigned .Where (x => x.RequestedNumber == CurrentRequest) .Select (x => { x.RequestCompleted = true; return x; }) If you want to create a new List with each element set to a value, you can do this: If you really want to do it using ForEach/LINQ, it's possible to abuse Select (but I don't recommend it): Can you describe some use cases of how you propose to use the said delegate? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Avoiding it would require enumerating the collection: Again, I wouldn't recommend this. The i.age = 10 part is not different from the item.age = 10 part. Why is it shorter than a normal address? In my application I have a list of items I need to sort by price and set a rank/position index for each item. What should I follow, if two altimeters show different altitudes? Your code is O(n m), where n is the length of a and m is the length of b. What were the most popular text editors for MS-DOS in the 1980s? rev2023.5.1.43405. What is the Efficiency and Performance of LINQ and Lambda Expression in .Net? If you want to modify all returned objects, you still have to use a loop to iterate over the objects. Can my creature spell be countered if I cast a split second spell after it? Making statements based on opinion; back them up with references or personal experience. Two MacBook Pro with same model number (A1286) but different year. ), Ubuntu won't accept my choice of password. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. It can be done this way as well foreach (Company company in listofCompany.Where(d => d.Id = 1)).ToList()) I'm not happy yet. To learn more, see our tips on writing great answers. Not the answer you're looking for? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Thanks for contributing an answer to Stack Overflow! foreach(var item in self) { What are the advantages of running a power tool on 240 V vs 120 V? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. What is the best way to give a C# auto-property an initial value? Since you save your result to a new List anyway, you can just Select the result instead: Oh and % wont do you any good here anyway, your number would be converted to int first, if it works at all. int index = mylist.FindIndex (p => p.id == 1); if (index<0) { mylist.Add (car3); } else { mylist [index] = car3; } This just uses the existing FindIndex to Folder's list view has different sized fonts in different folders. Was Aristarchus the first to propose heliocentrism? I guess what I'm really saying here is I want a concise way to set all elements of a multi-dimensional array to a given value. You can use Magiq, a batch operation framework for LINQ. I assume you want to change values inside a query so you could write a function for it UPDATE This can be simplified to be listOf If the null hypothesis is never really true, is there a point to using a statistical test without a priori power analysis? 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. Find centralized, trusted content and collaborate around the technologies you use most. EDIT: Short story about swapping bodies as a job; the person who hires the main character misuses his body. If you want to create a new List with each element set to a value, you can do this: var changes = Enumerable.Range (0, width) .Select (x => Remember that linq is a querying language, which means all you can do is query it. It's not LINQ, and it's not really much different to your nested for loops, just slightly less verbose. Let me try to look it up. Making statements based on opinion; back them up with references or personal experience. Using LINQ to change values in collection, How a top-ranked engineering school reimagined CS curriculum (Ep. Where can I find a clear diagram of the SPECK algorithm? I'm trying this but can't get it right: rev2023.5.1.43405. I've tried using ForEach and various forms of select, etc.. nothing seems to work right. You need change increment to postfix (rankPosition++) or initial value of rankPosition to 0. Could a subterranean river or aquifer generate enough continuous momentum to power a waterwheel for the purpose of producing electricity? Find centralized, trusted content and collaborate around the technologies you use most. Use MathJax to format equations. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. To learn more, see our tips on writing great answers. Why is it shorter than a normal address? Unexpected uint64 behaviour 0xFFFF'FFFF'FFFF'FFFF - 1 = 0? Here is one way to rewrite your method to use LINQ: public static int GetItemIndex(string search) { List _list = new List() { "one", "two", At the moment I am doing it like this: You could do it using the let keyword. Also, you What is Wario dropping at the end of Super Mario Land 2 and why? 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. It's about querying, i.e. For Starship, using B9 and later, how will separation work if the Hydrualic Power Units are no longer needed for the TVC System? To learn more, see our tips on writing great answers. Besides checking for it's existance with if, first. It's also a violation of the expectations involved with LINQ - LINQ is about querying, which suggests there shouldn't be side effects when using LINQ, and the entire purpose here is to create side effects. Connect and share knowledge within a single location that is structured and easy to search. Very useful. x.Value = Convert.ToDouble(string.Format("{0:0.0}", x)) : x.Value = x.Value); This gives you an this would be used for thing done to each date time as opposed to thing done with each date time That would be slightly different. Since you want to change the properties of the elements in your enumeration, you should not be using linq or List.ForEach for that. Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem? What were the most popular text editors for MS-DOS in the 1980s? He also rips off an arm to use as a sword, Identify blue/translucent jelly-like animal on beach, Ubuntu won't accept my choice of password. You can create a extension method: public static IEnumerable Do(this IEnumerable self, Action action) { Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey, Using LINQ to remove elements from a List, How to use LINQ to select object with minimum or maximum property value. Which language's style guidelines should be used when writing code that is supposed to be called from another language? How can I control PNP and NPN transistors together from one pin? A boy can regenerate, so demons eat him for years. Set list property value using LINQ ForEach. You could make it O ( n + m) (assuming only a small number of items from a match each item in b) by using a hash table. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Even by limiting it like this, it still takes around 3 min. Can anyone help me with a working expression? Use .ToList () in order to convert query in list that you can work with. For Starship, using B9 and later, how will separation work if the Hydrualic Power Units are no longer needed for the TVC System? 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. Did the drapes in old theatres actually say "ASBESTOS" on them? There's not a single query in LINQ that modifies the queried collection (hence "query"). You could make it O(n + m) (assuming only a small number of items from a match each item in b) by using a hash table. Not the answer you're looking for? I don't think this would help. 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. I'm querying to return every element of a List, so I can then set those values. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. He also rips off an arm to use as a sword. Find centralized, trusted content and collaborate around the technologies you use most.
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