make variables available outside function in PHP ?

Question

I have this function which declares variables:

function imageSize($name, $nr, $category){
    $path = 'ad_images/'.$category.'/'.$name.'.jpg';
    $path_thumb = 'ad_images/'.$category.'/thumbs/'.$name.'.jpg';
    list($width, $height) = getimagesize($path);
    list($thumb_width, $thumb_height) = getimagesize($path_thumb);
     ${'thumb_image_' . $nr . '_width'} = $thumb_width;
     ${'thumb_image_' . $nr . '_height'} = $thumb_height;
     ${'image_' . $nr . '_width'} = $width;
     ${'image_' . $nr . '_height'} = $height;
}

When I echo this:

   echo $image_1_width

It works fine, but if I do it OUTSIDE the function it wont recognize the variable, how can I make them 'global' somehow?

Thanks

Answer 1

You will have to define them outside of the function. And inside the function use the global keyword before you use them:

$someVar = null;

function SomeFunc () {
    global $someVar;
    // change $someVar
}

// somewhere later
SomeFunc ();
echo $someVar;

be advised though, that this is a really bad design choice!

Answer 2

Use global?

PHP: Variable scope - Manual

Answer 3

$var = 4;

function bla ()
{
  global $var;
  return $var;
}

It will return 4, because the variable is global. Hope this is what you want.

Answer 4

I would strongly advise NOT using global.

What will probably be best is for you to return from the fucntion:

function imageSize($name, $nr, $category){
    $path = 'ad_images/'.$category.'/'.$name.'.jpg';
    $path_thumb = 'ad_images/'.$category.'/thumbs/'.$name.'.jpg';
    list($width, $height) = getimagesize($path);
    list($thumb_width, $thumb_height) = getimagesize($path_thumb);
        ${'thumb_image_' . $nr . '_width'} = $thumb_width;
        ${'thumb_image_' . $nr . '_height'} = $thumb_height;
        ${'image_' . $nr . '_width'} = $width;
        ${'image_' . $nr . '_height'} = $height;

    $myarr = array();
    $myarr['thumb_image_' . $nr . '_width'] = $thumb_width;
    $myarr['thumb_image_' . $nr . '_height'] = $thumb_height;
    $myarr['image_image_' . $nr . '_width'] = $width;
    $myarr['image_image_' . $nr . '_height'] = $height;
    return $myarr;

}

$myImage = imageSize($name, $nr, $category);

then you access each var:

echo $myImage['thumb_image_1_width'];
echo $myImage['thumb_image_1_height'];
echo $myImage['image_1_weight'];
echo $myImage['image_1_height'];

etc

Answer 5

return the value inside the function instead of using globals

Answer 6

It sounds as though you'd like to implement a class rather than a function. Something like:

class myImage {

   function __construct($name, $nr, $category){
      $path = 'ad_images/'.$category.'/'.$name.'.jpg';
      $path_thumb = 'ad_images/'.$category.'/thumbs/'.$name.'.jpg';
      list($width, $height) = getimagesize($path);
      list($thumb_width, $thumb_height) = getimagesize($path_thumb);
      $this->{'thumb_image_' . $nr . '_width'} = $thumb_width; 
      $this->{'thumb_image_' . $nr . '_height'} = $thumb_height;
      $this->{'image_' . $nr . '_width'} = $width;
      $this->{'image_' . $nr . '_height'} = $height;  
   }
}

$image= new myImage($name, $nr, $category);
echo $image->'image_1_width';

Of course, with this sort of construction, you don't have to glue together variable names. You can just have $image->width.

Answer 7

You could also create an array or an object then return that - e.g.

$dimensions[$nr] = imageSize($name,$category);
echo "Thumb width " . $dimensions[$nr]['thumb_width'];

Then in the function itself

function imageSize($name, $category)
{
    $path = 'ad_images/'.$category.'/'.$name.'.jpg';
    $path_thumb = 'ad_images/'.$category.'/thumbs/'.$name.'.jpg';
    list($width, $height) = getimagesize($path);
    list($thumb_width, $thumb_height) = getimagesize($path_thumb);

    $rsvp = Array();
    $rsvp['thumb_width']  = $thumb_width;
    $rsvp['thumb_height'] = $thumb_height;
    $rsvp['image_width']  = $width;
    $rsvp['image_height'] = $height;

    return $rsvp;
}

Answer 8

I second @Lizard's answer. Also, it sounds like reading up on variable scope a bit wouldn't go amiss. (Note, that link does include explanation of how to use global variables. Like many here have said, that's not the best road to go down.)

Answer 9

I'm surprised that no one thought to tell you about extract. It will take the values from an array and turn them into local variables. So, in this case:

function imageSize($name, $nr, $category){
 $path = 'ad_images/'.$category.'/'.$name.'.jpg';
 $path_thumb = 'ad_images/'.$category.'/thumbs/'.$name.'.jpg';

 $myarr = array();
 $myarr['thumb_image_' . $nr . '_width'] = $thumb_width;
 $myarr['thumb_image_' . $nr . '_height'] = $thumb_height;
 $myarr['image_image_' . $nr . '_width'] = $width;
 $myarr['image_image_' . $nr . '_height'] = $height;
 return $myarr;

}

$myImage = imageSize('myName', 'foo', $category);
extract( $myImage );

You'll now have the variables,

$thumb_image_foo_width;
$thumb_image_foo_height;
$image_image_foo_width;
$image_image_foo_height;

in local scope.

Answer 10

If you declare the variable as part of the $GLOBALS array, you will be adding it to the global scope.

$GLOBALS['variable name'] = 'value';

As others have mentioned, globals should be initialized in the global scope, for example to NULL.