Ternary Operator

I have become a big fan of the ternary operator… It’s quite useful for replacing simple if-else statements.

Ternary operator template:

  ( true/false expression to evaluate  ) ? (true evaluation) : (false evaluation) ;

E.g.

bool IsMoCool = false;
string s = (IsMoCool) ? "Mo is cool" : "Mo is not cool";
Console.WriteLine(s);

Can you predict the result? This should print “Mo is not cool” to the console window. This happens for 2 reasons, the first is the “IsMoCool” value is initialized as false. So when the statement ( IsMoCool ) evaluated it yeilds a false value and executes the false condition. The 2nd reason this works is because mO is not cool!

Here is a better usage of the ternary operator…

Let’s say I have the following code…

public class TernaryDemo
{
  private object _myObject;

  public object MyObject 
  { 
    get { if( null == _myObject ) { _myObject = new object(); } return _myObject; } 
  }
}

This could be re-written as….

  public class TernaryDemo
  {
    private object _myObject;

    public object MyObject 
    {
      // if _myObject hasn't been constructed yet then create an instance,
      // otherwise return the constructed instance.
      get { return ( null == _myObject ) ? _myObject = new object() : _myObject; }
    }
  }

Recently I was reading an article from an MSDN blog… (I’m sorry I didn’t save the link… I will have to look it up later.) And I came across the ?? operator added in C# 2.0. Whoa!

Here’s how (I think) it works…

  private string _s;

  public void MyMethod() 
  {
    string s = ( null == _s) ?  "Some Clever Text Here" : _s;
  }

The above code can be re-written using ?? like this…

  private string _s;

  public void MyMethod() 
  {
    string s = _s ??  "Some Clever Text Here";
  }

The ?? operator implicitly does the same operation as the ternary operator but looks much cleaner. I’m not sure if I’m a fan yet, but I’d love to hear what you think!