c++

What does “static” mean in C?

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A static variable inside a function keeps its value between invocations. A static global variable or a function is “seen” only in the file it’s declared in (1) is the more foreign topic if you’re a newbie, so here’s an example: #include <stdio.h> void foo() { int a = 10; static int sa = 10; … Read more

How and when to use ‘async’ and ‘await’

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When using async and await the compiler generates a state machine in the background. Here’s an example on which I hope I can explain some of the high-level details that are going on: public async Task MyMethodAsync() { Task<int> longRunningTask = LongRunningOperationAsync(); // independent work which doesn’t need the result of LongRunningOperationAsync can be done … Read more

JavaScriptSerializer – JSON serialization of enum as string

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I have found that Json.NET provides the exact functionality I’m looking for with a StringEnumConverter attribute: using Newtonsoft.Json; using Newtonsoft.Json.Converters; [JsonConverter(typeof(StringEnumConverter))] public Gender Gender { get; set; } More details at available on StringEnumConverter documentation. There are other places to configure this converter more globally: enum itself if you want enum always be serialized/deserialized as … Read more

Create Generic method constraining T to an Enum

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Since Enum Type implements IConvertible interface, a better implementation should be something like this: public T GetEnumFromString<T>(string value) where T : struct, IConvertible { if (!typeof(T).IsEnum) { throw new ArgumentException(“T must be an enumerated type”); } //… } This will still permit passing of value types implementing IConvertible. The chances are rare though.

LINQ’s Distinct() on a particular property

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What if I want to obtain a distinct list based on one or more properties? Simple! You want to group them and pick a winner out of the group. List<Person> distinctPeople = allPeople .GroupBy(p => p.PersonId) .Select(g => g.First()) .ToList(); If you want to define groups on multiple properties, here’s how: List<Person> distinctPeople = allPeople … Read more

Send HTTP POST request in .NET

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There are several ways to perform HTTP GET and POST requests: Method A: HttpClient (Preferred) Available in: .NET Framework 4.5+, .NET Standard 1.1+, and .NET Core 1.0+. It is currently the preferred approach, and is asynchronous and high performance. Use the built-in version in most cases, but for very old platforms there is a NuGet … Read more

Path.Combine for URLs?

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Uri has a constructor that should do this for you: new Uri(Uri baseUri, string relativeUri) Here’s an example: Uri baseUri = new Uri(“http://www.contoso.com”); Uri myUri = new Uri(baseUri, “catalog/shownew.htm”); Note from editor: Beware, this method does not work as expected. It can cut part of baseUri in some cases. See comments and other answers.