<?php
$c = $_SERVER['CONTEXT'];

echo "->a: "; var_dump($c->a);
echo "['a']: "; var_dump($c['a']);
echo "isset: "; var_dump(isset($c->a));
echo "empty: "; var_dump(empty($c->a));
echo "exists: "; var_dump(property_exists($c, "a"));
echo "\n";

echo "->b: "; var_dump($c->b);
echo "['b']: "; var_dump($c['b']);
echo "isset: "; var_dump(isset($c->b));
echo "empty: "; var_dump(empty($c->b));
echo "exists: "; var_dump(property_exists($c, "b"));
echo "\n";

echo "->c: "; var_dump($c->c);
echo "['c']: "; var_dump($c['c']);
echo "isset: "; var_dump(isset($c->c));
echo "empty: "; var_dump(empty($c->c));
echo "exists: "; var_dump(property_exists($c, "c"));
echo "\n";

echo "->d: "; var_dump($c->d);
echo "['d']: "; var_dump($c['d']);
echo "isset: "; var_dump(isset($c->d));
echo "empty: "; var_dump(empty($c->d));
echo "exists: "; var_dump(property_exists($c, "d"));
echo "\n";

echo "->e: "; var_dump($c->e);
echo "['e']: "; var_dump($c['e']);
echo "isset: "; var_dump(isset($c->e));
echo "empty: "; var_dump(empty($c->e));
echo "exists: "; var_dump(property_exists($c, "e"));
echo "\n";

echo "->f: "; var_dump($c->f);
echo "['f']: "; var_dump($c['f']);
echo "isset: "; var_dump(isset($c->f));
echo "empty: "; var_dump(empty($c->f));
echo "exists: "; var_dump(property_exists($c, "f"));
echo "\n";

echo "->g: "; var_dump($c->g);
echo "['g']: "; var_dump($c['g']);
echo "isset: "; var_dump(isset($c->g));
echo "empty: "; var_dump(empty($c->g));
echo "exists: "; var_dump(property_exists($c, "g"));
echo "\n";

echo "->h: "; var_dump($c->h);
echo "['h']: "; var_dump($c['h']);
echo "isset: "; var_dump(isset($c->h));
echo "empty: "; var_dump(empty($c->h));
echo "exists: "; var_dump(property_exists($c, "h"));
echo "\n";

?>