Try it yourself editor for expressions

Hi, In my current work, I used to test expressions by putting trace and will look there in the trace file. It will be good if I have some try it yourself editor and I can see the results there itself. May be I don't have option of testing dynamic values, either I can some static manipulation of values. Something like this where I can see my results http://www.w3schools.com/css/tryit.asp?filename=trycss_default Thanks