C# questions:

What type of methods can be called without instantiating an object first?

static

dynamic

primary

Assume an extension method is defined as:

static class Util

{ public static int Negate(this int i)

{

return -i;

}

}

Which of the following is correct?

int x = 591; Console.WriteLine($"x.Negate {x.Negate()}");

int x = 591; Console.WriteLine($"x.Negate {Util.Negate(x)}");

both A and B

None of the above

To define an extension method for a type:

The extension method can be an instance method

The first parameter must be of the type being extended

The first parameter must be proceeded by this keyword

Both A, B and C

Both B and C

Both A and C

var addresses = new[] {

new { CompanyName = "Alpine Ski House", City = "Berne", Country = "Switzerland"},

new { CompanyName = "Coho Winery", City = "San Francisco", Country = "United States"},

new { CompanyName = "Wingtip Toys", City = "London", Country = "United Kingdom"},

new { CompanyName = "Wide World Importers", City = "Tetbury", Country = "United Kingdom"}

};

var usCompanies =

addresses.Where(addr => String.Equals(addr.Country, "United States"))

.Select(usComp => usComp.CompanyName)

What type is variable usCompanies?

int

string

IEnumerable

anonymous type