lambda

[Solved] Move duplicates of a list within the list c#

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You need to add a property ( i called it Others) to Employee to store the list employees .GroupBy(x => x.EmpID) .Select(g => { var byPres = g.OrderByDescending(x => x.DateofPresentation).ToArray(); var e = byPres.First(); e.Others = byPres.Skip(1).ToList(); return e; }) see demo https://dotnetfiddle.net/kRiMds 0 solved Move duplicates of a list within the list c#

[Solved] Perfect forwaring of auto&& in generic lambda

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In C++20 and later auto lambda20 = []<class F, class…Ts>(F &&fn, Ts &&…args) { return std::forward<F>(fn)(std::forward<Ts>(args)…); }; In C++pre20 : C++11,14,17 auto lambda14 = [](auto &&fn, auto &&…args) { return std::forward< std::conditional_t< std::is_rvalue_reference_v<decltype(fn)>, typename std::remove_reference_t<decltype(fn)>, decltype(fn)> >(fn)( std::forward< std::conditional_t<std::is_rvalue_reference<decltype(args)>::value, typename std::remove_reference<decltype(args)>::type, decltype(args) >>(args)…); }; Example #include <iostream> using namespace std; int main() { auto lambda20 … Read more

[Solved] Get All instead of FirstOrDefault

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You are using FirstOrDefault so you are returning only the first. PromotionList dataPromotion = authenticateCustomerResponseRootObject.Response.AuthenticateCustomerResponse.EligiblePromotions.PromotionList.Where(p => p.LineOfBusiness.ToUpper().Equals(“Data”)).FirstOrDefault(); If you want all of them just remove that call at the end and replace with a ToList, ToArray or similar that meets your needs: var data = authenticateCustomerResponseRootObject.Response.AuthenticateCustomerResponse.EligiblePromotions.PromotionList.Where(p => p.LineOfBusiness.ToUpper().Equals(“Data”)).ToList(); Also as mentioned in the comments your … Read more

[Solved] Lambda expressions in c#

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Try Select instead of Where to get a list of all can_main_key values: var candidate = db_can_records.CandidateMains.Select(m => m.can_main_key).ToList(); To get all the values for a single row of CandidateMains where you know the key try: var candidate = db_can_records.CandidateMains.FirstOrDefault(m => m.can_main_key == variableContainingRequiredId); solved Lambda expressions in c#

[Solved] Performance gain using anonymous functions? [closed]

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The question itself is easily answered, no there is no performance gain in using anonymous functions in Python. There is a good chance you are actually making it slower. A simple timeit tests on trivial functions show that there is no real difference between the two. We take these two functions def test(message): return message … Read more

[Solved] why this lambda expression do not work when in statement ,but work in method?

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In your second code version: Map<Object, Boolean> seen = new ConcurrentHashMap<>(); The map Map<> seen is initialized for every element x, therefore your filter always return true which will let all elements passthrough. Move the Map<> seen declaration to outside the lambda will correct your usage. In the first code version, the Map<> seen is … Read more

[Solved] PEP 8 warning “Do not use a lambda expression use a def” for a defaultdict lambda expression [duplicate]

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A lambda in Python is essentially an anonymous function with awkward restricted syntax; the warning is just saying that, given that you are assigning it straight to a variable – thus giving the lambda a name -, you could just use a def, which has clearer syntax and bakes the function name in the function … Read more

[Solved] Java Lambda Consumer Compilation behavior

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The problem is that your two lambdas could be using the value of datamap before it has been initialized. At least, that is what the JLS definite assignment rules are saying. This is what will happen when the ConsumerTest object is created: The bare object is allocated. The superclass constructor is called (Object()) which does … Read more