How To Create a Sequence of Numbers in C#

For some problems you need a sequence of numbers. In Python I would use the range() function, while in C# the method Enumerable.Range() gives us what we need. We must specify the starting point and how many numbers we want:

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IEnumerable<int> numbers = Enumerable.Range(1, 10);

foreach (int num in numbers)
{
    Console.WriteLine(num);
}

If we runt this code it prints the 10 numbers from 1 to 10:

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 4
 5
 6
 7
 8
 9
10
1
2
3
4
5
6
7
8
9
10

To be precise, Enumerable.Range() gives an IEnumerable back. This allows us to directly use the enumeration and do some operations on them (like calculating their squares):

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IEnumerable<int> squares = Enumerable.Range(1, 10).Select(x => x * x);

foreach (int num in squares)
{
    Console.WriteLine(num);
}

This time we get the squares back instead of the number 1 to 10:

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 7
 8
 9
10
1
4
9
16
25
36
49
64
81
100

Enumerable.Range() is easy to overlook. Before you create a loop to get the numbers you may go for a more direct approach and use the Range() function instead.