is ienumerable faster than list?
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IEnumerable doesn't allow random access, where as List does allow random access using integral index. In term of performance, iterating values from IEnumerable is much faster than iterating values from a List.
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Time complexity for ArrayDeque for accessing a element is O(1) and that for LinkList is is O(N) to access last element. ArrayDeque is not thread safe so manually synchronization is necessary so that you can access it through multiple threads and so they they are faster.
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There is a very important difference if the source of the data is Entity Framework: Find will find entities in the 'added' state that are not yet persisted, but Where will not. This is by design. Find is only implemented in List<T> , while Where(). FirstOrDefault() works with all IEnumerable<T> .
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IEnumerable is an interface defining a single method GetEnumerator() that returns an IEnumerator interface. This works for readonly access to a collection that implements that IEnumerable can be used with a foreach statement. IEnumerator has two methods MoveNext and Reset. It also has a property called Current.
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range() can actually be faster in some scenario if you iterating over the same sequence multiple times. xrange() has to reconstruct the integer object every time, but range() will have real integer objects. The results below shows that xrange is indeed faster, but not enough to sweat over.
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Dictionary uses a hash lookup, while your list requires walking through the list until it finds the result from beginning to the result each time. ... The list will be faster than the dictionary on the first item, because there's nothing to look up.
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List comprehension is faster because it is optimized for the Python interpreter to spot a predictable pattern during looping. Besides the syntactic benefit of list comprehensions, they are often as fast or faster than equivalent use of map .
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You can either use the so called Lambda expressions, which are based on operators, and have a method syntax. Or you can use Query expressions, which have an SQL like syntax. Although the two methods look very different, they are both 100% LINQ, and sends the exact same output to screen.
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Iterator and for-each loop are faster than simple for loop for collections with no random access, while in collections which allows random access there is no performance change with for-each loop/for loop/iterator.
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Tuple is stored in a single block of memory. Creating a tuple is faster than creating a list. Creating a list is slower because two memory blocks need to be accessed. An element in a tuple cannot be removed or replaced.
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6 Answers. Memcpy will probably be faster, but it's more likely you will make a mistake using it. It may depend on how smart your optimizing compiler is.
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The main difference between Iterator and Enumeration is removal of the element while traversing the collection. Iterator can remove the element during traversal of collection as it has remove() method. Enumeration does not have remove() method. ... Iterator is the interface and found in the java.
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Yes, streams are sometimes slower than loops, but they can also be equally fast; it depends on the circumstances. The point to take home is that sequential streams are no faster than loops.
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First() is slightly more efficient because it doesn't bother checking to see if there is a second item. The only difference is that Single() expects there to be only one item in the enumeration to begin with, and will throw an exception if there are more than one. You use .
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Add(new string[] { "Id", "Name", "Age" }); for(int i=0; i<list. Count; i++) for(int j=0; j<list[i]. Count(); j++) Console. WriteLine(list[i][j]); // simpler with foreach foreach(var l in list) foreach(string s in l) Console.
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The difference to List now is that List is untyped and therefore no type checks at all are performed, which ultimately leads to certain warnings and can lead to weird runtime behavior. While Java knows that List<Object> is a list that might contain anything, it doesn't know that about a List .
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A Generic collection is a class that provides type safety without having to derive from a base collection type and implement type-specific members. ... The key difference between Generic and Non-generic Collection in C# is that a Generic Collection is strongly typed while a Non-Generic Collection is not strongly typed.