array_intersect() Argument is not an array - php

Question

I have developed this small code to check if 2 text, one from a database and the other from an outside imput have common words.
The problem is that I get a message "Argument is not an array".
I cannot see where is the problem.
I also need to check if the 2 messages if should have the same words are in the same sequence.
Please help to understand where is the mistake.
Thanks
$checkMsg=strip_tags($_POST['checkMsg']); // message from input form
$message // message from database
$MsgWords = preg_split("/[\s,]+/", $checkMsg);
if(!empty($checkMsg)){
foreach ($MsgWords as $Neword)
{ $Neword = trim($Neword);
echo " $Neword";
}
$word = preg_split("/[\s,]+/", $message);
foreach ($word as $currentWord)
{
$currentWord = trim($currentWord);
echo " $currentWord";
}
$intersect=array_intersect( $Neword ,
$currentWord);
echo" Your common words are: $intersect";}else{echo "No common words";}

Answer 1

As others have said you're comparing the strings not the array. Your code should be something like this (you'll have to probably change this a little its just an example)
$checkMsg=strip_tags($_POST['checkMsg']); // message from input form
$message // message from database
$MsgWords = preg_split("/[\s,]+/", $checkMsg);
if(!empty($checkMsg)){
$intersect=array_intersect($message,$MsgWords);
if (count($intersect)>1) {
//only show output if there are matches
echo "Words in common are:<br />";
foreach ($intersect as $Neword) {
$Neword = trim($Neword);
echo $Neword."<br />";
}
} else {
echo "There are no words in common";
}
}

Answer 2

Okay, so firstly you're looping through the two arrays and changing the value, but the way you have it, you are just changing a temp copy of the value, not the value in the array. To do that, you need to use the & sign in the foreach() to tell it to use a reference variable in the loop, like this:
foreach ($MsgWords as &$Neword) { //added the & sign here.
$Neword = trim($Neword);
}
Do the same thing to the other foreach() loop too.
Secondly, your array_intersect() call is looking at the single strings, not at the whole arrays. You need it to look at the arrays:
//your incorrect version:
$intersect=array_intersect( $Neword, $currentWord);
//corrected version, using your variable names.
$intersect=array_intersect( $MsgWords, $word);
That should solve your problems.
[EDIT]
Also, note the array_intersect() outputs an array (ie the array of the intersection between the two input arrays). You can't use echo() to print an array directly. If you try, it will just show the word 'Array'. You need to convert it into a string first:
//your incorrect code.
echo "Your common words are: $intersect";
//corrected code:
echo "Your common words are: ".implode(',',$intersect);
I would also note that your coding style is very messy and hard to read. I strongly recommend trying to tidy it up; follow some kind of indentation and variable naming rules. Otherwise it will be very hard to maintain.