= Expression Tour =

This is a "tour" of various kinds of expressions in Cobra. It is not a reference manual for expressions, but is instead intended to help you learn Cobra.

== Displaying Expression Values ==

One of the best ways is to display an expression's value is to use the [wiki:Trace] statement which will show the source code of the expression, its value and the location of the trace in the source code (filename, line number, etc.):

{{{
#!python
trace p.x, p.y
}}}
{{{
    trace: p.x=5; p.y=6; at Foo.cobra:6; in Foo.main
}}}

You can, of course, use a [wiki:Print] statement. On a related note, you can validate the value of an expression with an [wiki:Assert] statement.