C# 7 and .NET Core 2.0 Blueprints

Pattern matching

Staying with the PopulateStorageSpacesList() method, we can see the use of another C# 7 feature called pattern matching. The spaces is null line of code is probably the simplest form of pattern matching. In reality, pattern matching supports several patterns.

Consider a switch statement:

switch (objObject) 
{ 
    case null: 
        WriteLine("null"); // Constant pattern 
        break; 
 
    case Document doc when doc.Author.Equals("Stephen King"): 
        WriteLine("Stephen King is the author"); 
        break; 
 
    case Document doc when doc.Author.StartsWith("Stephen"): 
        WriteLine("Stephen is the author"); 
        break; 
 
    default: 
        break; 
} 

Pattern matching allows developers to use the is expression to see whether something matches a specific pattern. Bear in mind that the pattern ...