Can you count how many times you wrote something like:
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| var prime = new bool[1000]; | |
| for ( int i = 0; i < isPrime.Length; i++ ) | |
| { | |
| prime[i] = true; | |
| } |
Or if you fancy LINQ (and can sacrifice a bit of performance)?
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| var prime = Enumerable.Repeat(true, 1000).ToArray(); |
If your answer is infinite or more, then check out the new way available in .NET Core 2.0 and newer:
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| var data = new bool[1000]; | |
| Array.Fill(data, true); |
Array.Fill brings the best of both worlds – it is more succinct than a for-loop while being more performant than Enumerable.Repeat.
As .NET Core is open source and we like to peek under the hood, we can see the Array.Fill method is basically just a shorthand for plain for loop:
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| public static void Fill<T>(T[] array, T value) | |
| { | |
| if (array == null) | |
| { | |
| ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array); | |
| } | |
| for (int i = 0; i < array.Length; i++) | |
| { | |
| array[i] = value; | |
| } | |
| } |
It is also worth mentioning that Array.Fill has another overload which lets us specify which range of indices should be filled:
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| public static void Fill<T> (T[] array, T value, int startIndex, int count); |
Thx and I translated your blog [dotnet core 用值初始化整个数组](https://lindexi.oschina.io/lindexi/post/dotnet-core-%E7%94%A8%E5%80%BC%E5%88%9D%E5%A7%8B%E5%8C%96%E6%95%B4%E4%B8%AA%E6%95%B0%E7%BB%84.html )