Initialize a List<int> with LINQ query
I am initializing a List<int>
in a constructor by storing two simple constants, MinValue and MaxValue as such:
private const int MinValue = 1;
private const int MaxValue = 100;
private List<int> integerList = new List<int>();
public Class()
{
for (int i = MinValue ; i < MaxValue ; i++)
{
integerList .Add(i);
}
}
Is there a way to just initialize the list with a simple LINQ query? Since a List<T>
can be constructed with an IEnumerable<T>
, does a 开发者_运维知识库query of the following form exist?
private List<int> integerList = new List<int>(<insert query here>);
Is this even possible?
This can be achieved using Enumerable.Range
List<int> integerList = Enumerable.Range(MinValue, MaxValue - MinValue).ToList();
Just use the Enumerable.Range(int start, int count)
method:
Generates a sequence of integral numbers within a specified range.
A simple example, using your MinValue
and MaxValue
variables:
List<int> integerList = Enumerable.Range(MinValue, MaxValue - MinValue).ToList();
Note that if MaxValue
is less than MinValue
, the count
parameter will be less than zero and an ArgumentOutOfRangeException
will be thrown.
Assuming MaxValue is always > MinValue,
var integerList = Enumerable.Range(MinValue, MaxValue-MinValue).ToList();
You could use a collection initializer.
http://msdn.microsoft.com/en-us/library/bb384062.aspx
private List integerList = new List{MinValue, MaxValue};
You could use Enumerable.Range
List<int> integerList = Enumerable.Range(MinValue, MaxValue - MinValue).ToList();
Try IEnumerable.Range(MinValue, MaxValue-MinValue).ToList(): MSDN
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