This weeks session was on LINQ and Silverlight.
LINQ
The LINQ session was a pretty basic roundup of some of the most common extension methods that you use with LINQ. Try filling out the blanks in the following code snippet
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LinqDemo
{
class Program
{
static void Main(string[] args)
{
List<Employee> employees = new List<Employee>
{
new Employee { FirstName = "AAA", LastName = "BBB", Age = 24, Weight = 75, Height = 1.78, Gender = Gender.Male },
new Employee { FirstName = "CCC", LastName = "DDD", Age = 24, Weight = 75, Height = 1.76, Gender = Gender.Male },
new Employee { FirstName = "EEE", LastName = "FFF", Age = 40, Weight = 110, Height = 1.78, Gender = Gender.Male },
new Employee { FirstName = "GGG", LastName = "HHH", Age = 39, Weight = 93, Height = 1.93, Gender = Gender.Male },
new Employee { FirstName = "III", LastName = "JJJ", Age = 24, Weight = 76, Height = 1.78, Gender = Gender.Male },
new Employee { FirstName = "KKK", LastName = "LLL", Age = 29, Weight = 65, Height = 1.57, Gender = Gender.Female },
new Employee { FirstName = "MMM", LastName = "NNN", Age = 34, Weight = 103.5, Height = 1.73, Gender = Gender.Male },
new Employee { FirstName = "OOO", LastName = "PPP", Age = 25, Weight = 77, Height = 1.86, Gender = Gender.Male },
new Employee { FirstName = "QQQ", LastName = "RRR", Age = 35, Weight = 82, Height = 1.8, Gender = Gender.Male },
new Employee { FirstName = "SSS", LastName = "TTT", Age = 34, Weight = 103.5, Height = 1.73, Gender = Gender.Male },
new Employee { FirstName = "UUU", LastName = "VVV", Age = 26, Weight = 90, Height = 1.74, Gender = Gender.Male },
new Employee { FirstName = "WWW", LastName = "XXX", Age = 34, Weight = 79, Height = 1.77, Gender = Gender.Male },
new Employee { FirstName = "YYY", LastName = "ZZZ", Age = 26, Weight = 90.5, Height = 1.72, Gender = Gender.Male },
new Employee { FirstName = "111", LastName = "222", Age = 34, Weight = 52, Height = 1.58, Gender = Gender.Female},
new Employee { FirstName = "333", LastName = "444", Age = 34, Weight = 90.5, Height = 1.76, Gender = Gender.Male }
};
// Find the average Weight
Console.WriteLine("Average Weight:\t{0}", null);
// Find the average age
Console.WriteLine("Average Age:\t{0}", null);
// Find the average BMI
Console.WriteLine("Average BMI:\t{0}", null);
// Find the number of females
Console.WriteLine("Females:\t{0}", null);
// Find the number of males
Console.WriteLine("Males:\t{0}", null);
// Is anyone a minor
Console.WriteLine("Do we have minors: {0}", null);
// Does everyone have a firstname longer than 3 characters
Console.WriteLine("Does everyone have a firstname longer than 3 characters: {0}", null);
// Create a long string of employee initials
Console.WriteLine("String of employee initials: {0}",
null);
// Group by genders and print the average height, weight and BMI
var genderGroups = null
foreach (var e in genderGroups)
{
Console.WriteLine("Averages for {0}s", e.Key.ToString());
Console.WriteLine("Weight:\t{0}", null);
Console.WriteLine("Height:\t{0}", null);
Console.WriteLine("BMI:\t{0}", null);
}
Console.ReadKey();
}
}
public class Employee
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public double Weight { get; set; }
public double Height { get; set; }
public string Name { get { return string.Format("{0} {1}", FirstName, LastName); } }
public Gender Gender { get; set; }
}
public enum Gender
{
Female,
Male
}
}
Solutions at the bottom (don’t peak!)
Silverlight
For silverlight we checked out an awesome demo financial application from the Microsoft Silverlight Showcase
LINQ Solution
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LinqDemo
{
class Program
{
static void Main(string[] args)
{
List<Employee> employees = new List<Employee>
{
new Employee { FirstName = "AAA", LastName = "BBB", Age = 24, Weight = 75, Height = 1.78, Gender = Gender.Male },
new Employee { FirstName = "CCC", LastName = "DDD", Age = 24, Weight = 75, Height = 1.76, Gender = Gender.Male },
new Employee { FirstName = "EEE", LastName = "FFF", Age = 40, Weight = 110, Height = 1.78, Gender = Gender.Male },
new Employee { FirstName = "GGG", LastName = "HHH", Age = 39, Weight = 93, Height = 1.93, Gender = Gender.Male },
new Employee { FirstName = "III", LastName = "JJJ", Age = 24, Weight = 76, Height = 1.78, Gender = Gender.Male },
new Employee { FirstName = "KKK", LastName = "LLL", Age = 29, Weight = 65, Height = 1.57, Gender = Gender.Female },
new Employee { FirstName = "MMM", LastName = "NNN", Age = 34, Weight = 103.5, Height = 1.73, Gender = Gender.Male },
new Employee { FirstName = "OOO", LastName = "PPP", Age = 25, Weight = 77, Height = 1.86, Gender = Gender.Male },
new Employee { FirstName = "QQQ", LastName = "RRR", Age = 35, Weight = 82, Height = 1.8, Gender = Gender.Male },
new Employee { FirstName = "SSS", LastName = "TTT", Age = 34, Weight = 103.5, Height = 1.73, Gender = Gender.Male },
new Employee { FirstName = "UUU", LastName = "VVV", Age = 26, Weight = 90, Height = 1.74, Gender = Gender.Male },
new Employee { FirstName = "WWW", LastName = "XXX", Age = 34, Weight = 79, Height = 1.77, Gender = Gender.Male },
new Employee { FirstName = "YYY", LastName = "ZZZ", Age = 26, Weight = 90.5, Height = 1.72, Gender = Gender.Male },
new Employee { FirstName = "111", LastName = "222", Age = 34, Weight = 52, Height = 1.58, Gender = Gender.Female},
new Employee { FirstName = "333", LastName = "444", Age = 34, Weight = 90.5, Height = 1.76, Gender = Gender.Male }
};
// Find the average Weight
Console.WriteLine("Average weight:\t{0}", employees.Average(e => e.Weight));
// Find the average age
Console.WriteLine("Average age:\t{0}", employees.Average(e => e.Age));
// Find the average BMI (weight / height^2)
Console.WriteLine("Average bmi:\t{0}", employees.Average(e => (e.Weight / Math.Pow(e.Height,2 ))));
// Find the number of females
Console.WriteLine("Number of Females:\t{0}", employees.Count(e => e.Gender == Gender.Female));
// Find the number of males
Console.WriteLine("Number of Males:\t{0}", employees.Where(e => e.Gender == Gender.Male).Count());
// Is anyone a minor
Console.WriteLine("Is anyone a minor:\t {0}", employees.Any(e => e.Age < 18) ? "Y" : "N");
// Does everyone have a firstname longer than 3 characters
Console.WriteLine("Does everyone have a firstname longer than 3 characters:\t {0}", employees.All(e => e.FirstName.Length > 3) ? "Y" : "N");
// Create a long string of employee initials
Console.WriteLine("Initials:\t {0}",
string.Join(",",
employees.Select(e => string.Format("{0}{1}", e.FirstName[0], e.LastName[0])).ToArray()));
// Using aggregates
Console.WriteLine("Initials:\t {0}",
employees.Aggregate(
string.Empty,
(collection, e) => string.Format("{0}{1}{2},", collection, e.FirstName[0], e.LastName[0])
)
);
// Group by genders and print averages
var results = employees.GroupBy(
g => g.Gender,
e => e);
foreach (var gender in results)
{
Console.WriteLine("Averages for '{0}'", gender.Key);
Console.WriteLine("\tWeight:\t {0}", gender.Average(e => e.Weight));
Console.WriteLine("\tHeight:\t {0}", gender.Average(e => e.Height));
Console.WriteLine("\tBMI:\t {0}", gender.Average(e => e.Weight / Math.Pow(e.Height, 2)));
Console.WriteLine();
}
Console.ReadKey();
}
}
public class Employee
{
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
public double Weight { get; set; }
public double Height { get; set; }
public string Name { get { return string.Format("{0} {1}", FirstName, LastName); } }
public Gender Gender { get; set; }
}
public enum Gender
{
Female,
Male
}
}