Contact: aviboots(AT)netvision.net.il
31,166 questions
40,722 answers
573 users
$var = ''; if (isset($var)) echo "yes"; /* run: yes */
$var = 'PHP'; var_dump(isset($var)); /* run: bool(true) */
var_dump(isset($var)); /* run: bool(false) */
$var; var_dump(isset($var)); /* run: bool(false) */
$var = "PHP"; var_dump(isset($var)); echo "<br />"; unset($var); var_dump(isset($var)); /* run: bool(true) bool(false) */
$var = null; var_dump(isset($var)); /* run: bool(false) */
$arr = array('aaa' => 1, 'bbb' => NULL); echo "<pre>"; var_dump(isset($arr['aaa'])); var_dump(isset($arr['bbb'])); var_dump(isset($arr['ccc'])); echo "</pre>"; /* run: bool(true) bool(false) bool(false) */
$s = 'PHP Startup or PHP start-up'; echo "<pre>"; var_dump(isset($s['PHP Startup or PHP start-up'])); // false var_dump(isset($s['PHP'])); // false var_dump(isset($s[0])); // true var_dump(isset($s['0'])); // true var_dump(isset($s[0.7])); // true var_dump(isset($s['0.7'])); // false var_dump(isset($s['0 PHP'])); // false echo "</pre>"; /* run: bool(false) bool(false) bool(true) bool(true) bool(true) bool(false) bool(false) */