Global variables in PHP [duplicate]

Answer 1

You need to declare $words global within the function itself. See:

$words = '';

function init_words($file)
{
    global $words;
    $words = file($file);
    $count = count($words);
    echo "$count words<br>\n"; // "3 words"
}

I suggest you review the variable scope chapter in the PHP manual.

As an aside I would never write this code in this way. Avoid globals unless they are absolutely necessary.

I would write your code this way to avoid this problem:

function init_words($file)
{
    $words = file($file);
    $count = count($words);
    echo "$count words<br>\n"; // "3 words"
    return $words;
}

$words = init_words("/foo/bar");
$count = count($words);
echo "$count words<br>\n"; // "3 words" 

Please see the returning values chapter in the PHP manual for more information on this.

Answer 2

Alternately, you could use the following and avoid usage of global altogether:

function init_words($fname)
{
    $w = file($fname, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);  // We don't want the trailing spaces or empty lines.
    $c = count($w);

    return array($w, $c);
}

list($words, $count) = init_words("Some_File.txt");

In such a situation if you ever had to do any manipulation of the list of words, you can handle it all within init_words() as opposed to elsewhere in the script.

Answer 3

$words = null;

function init_words($file)
{
    global $words;
    $words = file($file);
    $count = count($words);
    echo "$count words<br>\n"; // "3 words"
}

init_words("/foo/bar");
$count = count($words);
echo "$count words<br>\n"; // "0 words" 

The global part should go inside your function

side note: it is not always the best to use global operators

Answer 4

first you need to store the words in a serialised formant so that means

$file_location = "/foo/bar/words.txt";
$words = array("game", "cool", "why");
$words = serilize($words);
write_words_file($words, $filelocation); //Create the function so it can write to a file

then you will need to edit your init_words

function init_words($file)
{
    global $words;
    $data = file_get_contents($file);
    $words = unserialize($data);
    $count = count($words);
    echo "$count words<br>\n"; // "3 words"
}

init_words("/foo/bar/words.txt");
$count = count($words);
echo "$count words<br>\n"; // "0 words" 

Answer 5

You want global $words; inside the function. Better yet, use the superglobal $GLOBALS.