C# LINQ Test – 2

1. In the following C# code, what does the output represent?

class Program
{
    static void Main(string[] args)
    {
        int[] nums = { 1, -2, 3, 0, -4, 5 };
        var posNums = from n in nums
                      where n > 0
                      select n;
        int len = posNums.Count();
        Console.WriteLine(len);
        Console.ReadLine();
    }
}

2. What will be the output of the following C# code snippet?

 class Program
 {
     static void Main(string[] args)
     {
         int[] nums = { 1, -2, 3, 0, -4, 5 };
         var posNums = nums.Where(n => n > 0).Select(r => r*2).
                       OrderByDescending(r=>r);
         Console.Write("The positive values in nums: ");
         foreach(int i in posNums) 
         Console.Write(i + " ");
         Console.WriteLine();
         Console.ReadLine();
     }
 }

3. What will be the output of the following C# code snippet?

 class Program
 {
     static void Main(string[] args)
     {
         int[] nums = {3, 1, 2, 5, 4};
         var ltAvg = from n in nums
                     let x = nums.Average()
                     where n < x
                     select n;
         Console.WriteLine("The average is " + nums.Average());
         Console.ReadLine();
     }
 }

4. What will be the output of the following C# code snippet?

 class Program
 {
     static void Main(string[] args)
     {
         int[] nums = { 1, -2, 3, 0, -4, 5 };
         var posNums = nums.Where(n => n < 10).Select(r => r%3);
         Console.Write("The values in nums: ");
         foreach (int i in posNums) Console.Write(i + " ");
         Console.WriteLine();
         Console.ReadLine();
     }
 }

5. What will be the output of the following C# code snippet?

class Program
{
    static void Main(string[] args)
    {
        Expression<Func<int, int, bool>>
        IsFactorExp = (n, d) => (d != 0) ? (n % d) == 0 : false;
        Func<int, int, bool> IsFactor = IsFactorExp.Compile();
        if (IsFactor(10, 5))
        Console.WriteLine("5 is a factor of 10.");
        if (!IsFactor(343, 7))
        Console.WriteLine("7 is not a factor of 10.");
        Console.ReadLine();
    }
}

6. Choose the namespace in which Expression trees are encapsulated?

7. In the following C# code, which query will work according to the set of code?

class Program
{
    static void Main(string[] args)
    {
        int[] nums = { 1, -2, 3, 0, -4, 5 };
        int len = /*_________________ */
        Console.WriteLine("The number of positive values in nums: " + len);
        Console.ReadLine();
    }
}

8. What will be the output of the following C# code snippet?

class Program
    {
        static void Main(string[] args)
        {

            int[] nums = { 1, -2, -3, 5 };
            var posNums = from n in nums
                          orderby n descending
                          select n*4 / 2;
            Console.Write("The values in nums: ");
            foreach (int i in posNums) Console.Write(i + " ");
            Console.WriteLine();
            Console.ReadLine();
        }
    }

9. What will be the output of the following C# code snippet?

class Program
{
    static void Main(string[] args)
    {
        string[] strs = { ".com", ".net", "facebook.com", "google.net", 
                         "test", "netflix.net", "hsNameD.com" };
        var netAddrs = from addr in strs
                       where addr.Length > 4 && addr.EndsWith(".net",
                       StringComparison.Ordinal)
                       select addr;
        foreach (var str in netAddrs) Console.WriteLine(str);
        Console.ReadLine();
    }
}

10. What will be the output of the following C# code snippet?

class Program
{
    static void Main(string[] args)
    {
        string[] strs = {"alpha", "beta", "gamma"};
        var chrs = from str in strs
                   let chrArray = str.ToCharArray()
                   from ch in chrArray
                   orderby ch
                   select ch;
        Console.WriteLine("The individual characters in sorted order:");
        foreach (char c in chrs) 
        Console.Write(c + " ");
        Console.WriteLine();
        Console.ReadLine();
    }
}