Filter the values in a flat array using a regular expression

Question

I have an array of words and an array of stopwords. I want to remove those words from the array of words that are in the stopwords array, but the code returns all words:

function stopwords($x){
      return !preg_match("/^(.|a|car|red|the|this|at|in|or|of|is|for|to)$/",$x);
    };

$filteredArray = array_filter($wordArray, "stopwords");

Why?

Answer 1

$wordArray = ["hello","red","world","is"];

function stopwords($x){
      return !preg_match("/^(.|a|car|red|the|this|at|in|or|of|is|for|to)$/",$x);
    };

$filteredArray = array_filter($wordArray, "stopwords");
var_dump($filteredArray);

# results out:
array(2) {
   [0] =>   string(5) "hello"   
   [2] =>   string(5) "world"
}

What do you think it was going to return?

Is your input '$wordArray' a string, or an array?