php best debugging functions
<?php
$myVar = "hello world!";
var_dump($myVar);
print_r($myVar);
$allVars = get_defined_vars();
print_r($allVars);
debug_zval_dump($allVars);
function sayHello($hello) {
echo $hello;
debug_print_backtrace();
}
sayHello($myVar);
?>