Friday 9 January 2015

C# 6 (Part 2)

String Interpolation

String interpolation is a replacement/alternative to string.format.

 var name = "Rob";  
 var output = "Hello \{name}";  

This will output "Hello Rob"

This is quite a nice feature as I find the syntax a lot easier to read than string.format.

Resharper 9.1 does not support this yet and will highlight it as an error, but it still compiles and runs.

nameof Operator

Quick and easy way of getting the name of something
 Console.WriteLine(nameof(test));  // varable outputs: "test"
 Console.WriteLine(nameof(TestProperty));  // property outputs: "TestProperty"
 Console.WriteLine(nameof(MyClass.TestProperty));  // property of class outputs: "TestProperty"
 Console.WriteLine(nameof(System.Text));   // namespace outputs: "Text"
 Console.WriteLine(nameof(MyClass.Method));  // method outputs: "Method"

Another useful little feature for when you are setting things using reflection and don't want to use strings, you can use an expression tree but this is simpler and I assume more efficient.

Resharper 9.1 does not support yet but it still compiles and runs

Expression Bodied Members

You can now define fields with lambda expressions.

 private int _total => _first + _second;  
 private static Program CreateProgram => new Program();  

Can also be used to define methods.

 public int Add(int x) => _number += x;  

Nice little feature for quick definition of simple methods.

Exception Filters
It is now possible to filter exceptions without affecting the stack trace.
 catch (Exception e) if (e is InvalidDataException || e is InvalidOperationException)  
   // Handle it  

This can also be used (abused) to log exceptions.
 catch (Exception e) if (Log(e))  
   // Handle it  
This seems to be an acceptable abuse of the feature as it is described in the language spec :)

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