Debug functions that will help you:
[...] = optional ... = your value
call dump_vars call dump_functions call args $foo=bar;$x=y;a=1 call execution_time
Show as text
Reload
Array
(
    [0] => test_function_0
    [1] => test_function_1
)
Array
(
    [cpy] => 1
    [func] => debugging_tools
    [rnd] => 979653103
    [url] => 
    [___t] => 
    [__xtblog_rss] => 
    [$my_var] => my value
    [$my_other_var] => my other value
    [$html] => 
hello
)

Better dump_vars

[cpy] => 1
[func] => debugging_tools
[rnd] => 979653103
[url] =>
[___t] =>
[__xtblog_rss] =>
[$my_var] => my value
[$my_other_var] => my other value
[$html] => <div>hello</div>
0.000000s.