Select - Filtered

Query

public void Linq13()
{
    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };
    string[] digits = { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };
  
    var lowNums =
        from n in numbers
        where n < 5
        select digits[n];
  
    Console.WriteLine("Numbers < 5:");
    foreach (var num in lowNums)
    {
        Console.WriteLine(num);
    }
}

Lambda Expression

public void DataSetLinq13()
{
    var numbers = testDS.Tables["Numbers"].AsEnumerable();
    var digits = testDS.Tables["Digits"];
 
    var lowNums = numbers.Where(n => n.Field("number") < 5).Select(n => digits.Rows[n.Field("number")].Field("digit"));
 
    Console.WriteLine("Numbers < 5:");
    foreach (var num in lowNums)
    {
        Console.WriteLine(num);
    }
}

Output

Numbers < 5:
four
one
three
two
zero