public void AnExampleOfThenBy()
{
var people = GetPeople().ToList();
people.Add(new Person()
{
Name = "Bob", Age = 5
});
var expected = new[] { new Person()
{
Name = "Alice", Age = 29
},
new Person()
{
Name = "Bob", Age = 5
},
new Person()
{
Name = "Bob", Age = 40
},
new Person()
{
Name = "Chuck", Age = 25
} };
var result = people.OrderBy(x => x.Name).ThenBy(x => x.Age);
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfOrderBy()
{
var people = GetPeople();
var expected = new [] { "Alice", "Bob", "Chuck" };
var result = people.OrderBy(x => x.Name).Select(x => x.Name);
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfTake()
{
var numbers = Enumerable.Range(1, 100);
var expected = Enumerable.Range(1, 10);
var result = numbers.Take(10);
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfSkip()
{
var numbers = new[] { 2, 4, 6, 8, 10 };
var expected = new[] { 8, 10 };
var result = numbers.Skip(3);
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfZip()
{
var letters = new[] { "A", "B", "C", "D", "E" };
var expected = new[] { "4 = A", "7 = B", "2 = C", "5 = D", "9 = E" };
var result = Numbers.Zip(letters, (x, y) => x + " = " + y);
BetterAssert.AreEqual(expected, result);
}
public void TheSameExampleOfSelectManyInMethodSyntax()
{
var list = new[] { "1,2,3", "4,5", "6,7,8" };
var expected = new[] { "1", "2", "3", "4", "5", "6", "7", "8" };
var result = list.SelectMany(item => item.Split(','));
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfOrderByDescending()
{
var people = GetPeople();
var expected = new[] { 40, 29, 25 };
var result = people.OrderByDescending(x => x.Age).Select(x => x.Age);
BetterAssert.AreEqual(expected, result);
}
public void WhichOneShouldIUse()
{
var methodResult = GetStudents().SelectMany(kid => kid.Subjects, (kid, subject) => kid.Name + " has " + subject);
var queryResult = from kid in GetStudents()
from subject in kid.Subjects
select kid.Name + " has " + subject;
// They are the same, so write the one that is easier to read!
BetterAssert.AreEqual(methodResult, queryResult);
}
public void AnExampleOfConcat()
{
var first = Enumerable.Range(1, 5);
var second = Enumerable.Range(6, 5);
var expected = Enumerable.Range(1, 10);
var result = first.Concat(second);
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfExcept()
{
var first = Enumerable.Range(1, 5);
var second = Enumerable.Range(4, 7);
var expected = new[] { 1, 2, 3 };
var result = first.Except(second);
BetterAssert.AreEqual(expected, result);
}
public void AnExample()
{
var expected = new List <int>()
{
1, 2, 3, 4, 5
};
var result = numbers.Where(number => number < 6);
BetterAssert.AreEqual(expected, result);
}
public void AnExample()
{
var expected = new List <string>()
{
"Color: Red", "Color: Green", "Color: Blue", "Color: Yellow", "Color: Black"
};
var result = colors.Select(color => "Color: " + color);
BetterAssert.AreEqual(expected, result);
}
public void TheSameExampleOfSelectManyInQuerySyntax()
{
var list = new[] { "1,2,3", "4,5", "6,7,8" };
var expected = new[] { "1", "2", "3", "4", "5", "6", "7", "8" };
var result = from item in list
from number in item.Split(',')
select number;
BetterAssert.AreEqual(expected, result);
}
public void QuerySyntax()
{
var expected = new List <int>()
{
1, 2, 3, 4, 5
};
var result = from number in numbers
where number <= 5
select number;
BetterAssert.AreEqual(expected, result);
}
public void TheSameExampleOfJoinWithMethodSyntax()
{
var expected = new[] { new { CourseName = "Math", PeriodName = "Fall" },
new { CourseName = "History", PeriodName = "Fall" },
new { CourseName = "Math", PeriodName = "Spring" },
new { CourseName = "Geography", PeriodName = "Spring" } };
var results = GetCourses().Join(GetMarkingPeriods(), course => course.SemesterId,
period => period.SemesterId,
(course, period) => new { course.CourseName, PeriodName = period.SemesterName }
);
BetterAssert.AreEqual(expected, results);
}
public void AnExampleOfJoin()
{
var expected = new [] { new { CourseName = "Math", PeriodName = "Fall" },
new { CourseName = "History", PeriodName = "Fall" },
new { CourseName = "Math", PeriodName = "Spring" },
new { CourseName = "Geography", PeriodName = "Spring" } };
var results = from course in GetCourses()
join period in GetMarkingPeriods()
on course.SemesterId equals period.SemesterId
select new { course.CourseName, PeriodName = period.SemesterName };
BetterAssert.AreEqual(expected, results);
}
public void MethodSyntax()
{
var expected = new List <int>()
{
1, 2, 3, 4, 5
};
// This would more accurately match the above query, but the Select is redundant if you're writing it yourself
//var result = numbers.Where(number => number <= 5).Select(number => number);
var result = numbers.Where(number => number <= 5);
BetterAssert.AreEqual(expected, result);
}
public void WithoutLinq()
{
var expected = new List <string>()
{
"Color: Red", "Color: Green", "Color: Blue", "Color: Yellow", "Color: Black"
};
var result = new List <string>();
foreach (var color in colors)
{
result.Add("Color: " + color);
}
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfSelectManyWithoutLinq()
{
var list = new[] { "1,2,3", "4,5", "6,7,8" };
var expected = new[] { "1", "2", "3", "4", "5", "6", "7", "8" };
var result = new List <string>();
foreach (var item in list)
{
foreach (var number in item.Split(','))
{
result.Add(number);
}
}
BetterAssert.AreEqual(expected, result);
}
public void AnExampleOfGroupBy()
{
var courses = GetCourses();
var result = courses.GroupBy(x => x.CourseName);
var expectedGroups = 3;
Assert.AreEqual(expectedGroups, result.Count());
var expectedKeys = new [] { "Math", "History", "Geography" };
BetterAssert.AreEqual(expectedKeys, result.Select(x => x.Key));
var expectedItemsInMathtGroup = 2;
Assert.AreEqual(expectedItemsInMathtGroup, result.Single(x => x.Key == "Math").Count());
}
public void WhereWithoutLinq()
{
var expected = new List <int>()
{
1, 2, 3, 4, 5
};
var result = new List <int>();
foreach (var number in numbers)
{
if (number < 6)
{
result.Add(number);
}
}
BetterAssert.AreEqual(expected, result);
}