in_array multiple word problem

I can't seem to find a solution to an issue related to the in_array command.  If my array contain single words, it works fine.  But if the array contains words  :facewall:separated by a space, in_array does not work.

Example:

$states = array();

$states[0] = "Alabama";

$states[1] = "North Dakota";

in_array finds Alabama but not North Dakota.  Does anyone have suggestions for how to make in_array work with multiple words or can you suggest another command to do the same thing?

foreach($states as $id=>$word){

if(in_array($word,$ex)){

$correct++;

}

What does $ex contain?

$ex = explode(' ', $essay);

essay is text that is typed into a textarea form.

You can see the demo at:

http://www.davislegal.net/essays/sample_form.php

$ex = explode(' ', $essay);

meaning $ex contains North, Dakota (two separate words) and not North Dakota (one whole word)

meaning that if I type "One of my friends lives in Alabama and the other lives in North Dakota" the [0] alabama is found but not [1] north dakota

I really appreciate any help you guys can provide.  I have been working on this for days and can't seem to get it right.  There MUST be an easy way to do this!  A visitor types words into a form which is submitted and those words are compared to words in an array using the in_array command.

Rather than using explode, try strpos() for each state. If the strpos is not false, you know the state is in there. There may be a way to do it with an array but this is the first way that comes to my mind.

Thanks for the tip.  I tried it but receive an error.  I'll spend some time understanding the command, but it looks like it finds the position of the first char in the string.

Correct. So you know as long as it returns a number 0 or more, it was found. So if it finds it, you can add that state to your list of ones found.

Use of the command strpos does work - THANKS!!  Now I'm have the problem with similar words.  Example: If I enter "AL ALA ALABAMA" all three words are found using strpos.  I understand why this happens, but I need it to be an exact match.  I've tried to use explode but that doesn't find any of the words.

<snip>

$ex = explode(' ', $essay);

// Loop through all of the $key_words array

foreach($key_words as $id=>$word){

$StringPos = strpos($essay,$word);

if ($StringPos === false) {

    echo "The keyword '$word' was not found in the string '$essay'<br>";

} else {

    echo "The keyword '$word' was found in the string '$essay'<br>";

    echo " and exists at position $StringPos<br>";

    $correct++;

    echo "Inside strpos:".$correct."<br>";

}

<snip>

That Works, but if I use $ex instead of $essay, it does not work.  Any thoughts?

<?php
$states = array("California", "North Dakota", "Rhode Island", "Virginia");

$essay = "Theres a small restaurant just north of North Dakota where you can find
          clam chowder, similar to that found in Rhode Island. Virginia has terrible
          sea food and California imports all it's sea food from Mexico";
          
foreach($states as $state)
{
    if(preg_match('/'. $state .'/i', $essay))
    {
        $found[] = $state;
    }
}

print_r($found);
?>

Output

Array
(
    [0] => California
    [1] => North Dakota
    [2] => Rhode Island
    [3] => Virginia
)

In regular expressions you can also use word boundaries. E.g. \bAl\b will only match Al in Al lives in Alabama. Code example:

<?php
$search = 'Al';
$essay = 'Al lives in Alabama, more than 1500 miles from North Dakota.';
$count = preg_match_all('~\b' . preg_quote($search, '~') . '\b~i', $essay, $matches);
echo "$search was found $count time(s) in the essay.";
?>

preg_quote() prepares $search for the regular expressions pattern, escaping special characters. the i after the closing pattern delimiter ~ makes the search case-insensitive.