This function displays structured information about one or more
expressions that includes its type and value. Arrays and objects are
explored recursively with values indented to show structure.
In PHP 5 all public, private and protected properties of objects will be
returned in the output.
Tip
As with anything that outputs
its result directly to the browser, the output-control functions can be used to capture
the output of this function, and save it in a
string (for example).