_exists function
bool function_exists (string function_name)
bool method_exists (object object, string method_name)
bool class_exists (string class_name [, bool autoload])
bool interface_exists (string interface_name [, bool autoload])
<?php
if (function_exists($isemail)){
if (isemail($email)){
} else {
echo "Not a valid e-mail address.";
}
} else {
echo "Function does not exist.<br />";
}
if (class_exists (myparent)){
class anyclass extends myparent {
public $somemember;
public function dosomething (){
if (method_exists (parent,"parentmethod")){
} else {
}
}
}
} else {
echo "Class does not exist.<br />";
}
if (isset ($_POST['searchterm'])){
} else {
echo "You must submit a search term. Please press the Back button.";
}
?>
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