Echo command can be used for quick debug message. You can comment them off when not in use.
echo "message line";
// echo "message line"; commented off
USING VAR_DUMP() TO AID YOUR DEBUGGING
var_dump() is a native PHP function which displays structured, humanly readable, information about one (or more) expressions. This is particularly useful when dealing with arrays and objects as var_dump() displays their structure recursively.
echo '<pre>'; var_dump($aMyData); echo '</pre>';
Tip: Wrap var_dump() in <pre> tags to aid readability.
Sometimes you may want to collect the log messages
in separate file instead of showing it in the browse.
You can log data to the standard error log file with error_log.
http://php.net/manual/en/function.error-log.php
PHP does not come with different debug levels (info, warning, error), you may also
standalone log modules/classes like Monolog or KLogger.
Monolog: https://github.com/Seldaek/monolog
KLogger: http://codefury.net/projects/klogger/
Besides var_dump(), you could also use var_export and print_r() functions in PHP
to examine variable values.
print_r() displays information about a variable in a way that's readable by humans.
print_r(), var_dump() and var_export() will also show protected and private properties of objects with PHP 5. Static class members will not be shown.
