Comparing two identical strings returns false in PHP

I'm trying to compare two strings. When I echo them, they appear to be identical, yet when I compare them with the '==' operator, it returns false. For example, when running the code below on my database. It outputs things like "APPARENTLY Apple does not equal Apple". What is the reason?

if ($this->data['list_text']) { // The user has entered into textarea

    $l开发者_如何学JAVAist = nl2br($this->data['list_text']);

    $list_array = explode('<br />', $list);

    $ranking = 1;
    $company_array = $this->CompanyList->CompanyRanking->Company->find('list', null);

    // This is the comparison bit
    foreach ($list_array as $key => $value) {
        $companyId = null;
        foreach ($company_array as $key2 => $value2) {
            if ($value2 != $value) {
                echo 'APPARENTLY ' . $value2 . ' does not equal ' . $value;
            } else {
                $companyId = $key2;
                break;
            }
        }

        $this->data['CompanyRanking'][$ranking]['ranking'] = $ranking;
        $this->data['CompanyRanking'][$ranking]['company_id'] = $companyId;
        $ranking++;
    }
}

Try var_dump() instead of echo.

echo 'APPARENTLY '.$value2.' does not equal '.$value;   
echo '<pre>Debug: ';
echo 'value='; var_dump($value);
echo 'value2='; var_dump($value2);
echo '</pre>';

It provides additional information. E.g. the actual type. And the length of strings.

Do the strings have any extra whitespace you're not seeing? Try trimming them.

Try to check the encoding of both strings compared.

Maybe it is UTF-8 compared with ISO 8859-1 with some weird characters.

I agree with Olafur. I removed trim and replaced it with a preg_replace due to the fact you are assuming $value and $value2 are companyIDs. You can make a quick modification on these if the companyID is supposed to be alphanumeric, contain hyphens, etc... This version should do it:

if ($this->data['list_text']) { 
    $list = nl2br($this->data['list_text']);
    $list_array = explode('<br />', $list);

    $ranking = 1;
    $company_array = $this->CompanyList->CompanyRanking->Company->find('list',null);

    foreach ($list_array as $key => $value) {

        // remove any non digit characters
        $value = preg_replace('/[^0-9]/i','', $value); 
        $companyId = null;

        foreach ($company_array as $key2 => $value2) {

            // remove any non digit characters
            $value2 = preg_replace('/[^0-9]/i','', $value2); 

            if ($value2 != $value) {
                echo 'values not equal';                
            } else {
                $companyId = $key2;
                break;
            }
        }

        $this->data['CompanyRanking'][$ranking]['ranking'] = $ranking;
        $this->data['CompanyRanking'][$ranking]['company_id'] = $companyId;
        $ranking++;
    }
}

Try trim() for any white space as well as var_dump() to see if anything else is being passed with it.