PHP If statement disallowing certain words from an array - php

Question

Just after some help, I have an array with disallowed words in which I cant show here as they are obscene.
What I want to do is check if $_POST['urlprefix'] != one of the array elements, I am wondering what the easiest way to do this is. Obviously the below only stops one element of the array.
Thanks for any help you may provide
if($_POST['urlprefix'] != $arr[1]) {
print("You've Passed");
} else {
print("You Are Not Allowed To Use That URL Prefix");
}

Answer 1

The examples with in_array() are a quick way to achieve that. You can also use a case-insensitive in_array function by using preg_grep.
But, if ship is a bad word, do you want to allow shippy ? The following code will forbid any prefixes that contain the word, too.
$disallow = false;
foreach($arr as $bad_word) {
if(stripos($_POST['urlprefix'], $bad_word) !== false) {
$disallow = true;
break;
}
}
if($disallow) {
die('Bad words in URL!');
}

Answer 2

You can use the in_array function :
if (!in_array($_POST['urlprefix'], $arr))
{
print("You've Passed");
}
else
{
print("You Are Not Allowed To Use That URL Prefix");
}
http://www.php.net/manual/fr/function.in-array.php

Answer 3

You can use this way. in_array is slower than this method. See more about array_flip.
$words = array('damn','shit');
$flip = array_flip($words);
if(!isset($flip[$_POST['urlprefix']])){
//valid url
}

Answer 4

You can use php in_array function. It checks if a value exists in an array
if(!in_array($_POST['urlprefix'], $arr)) {
print("You've Passed");
} else {
print("You Are Not Allowed To Use That URL Prefix");
}