PHP 5.4.31 Released
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User Contributed Notes 3 notes

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17
Anonymous
3 years ago
The keyword 'use' has two different applications, but the reserved word table links to here.

It can apply to namespace constucts:

file1:
<?php namespace foo;
  class
Cat {
    static function
says() {echo 'meoow';}  } ?>

file2:
<?php namespace bar;
  class
Dog {
    static function
says() {echo 'ruff';}  } ?>

file3:
<?php namespace animate;
  class
Animal {
    static function
breathes() {echo 'air';}  } ?>

file4:
<?php namespace fub;
  include
'file1.php';
  include
'file2.php';
  include
'file3.php';
  use
foo as feline;
  use
bar as canine;
  use
animate;
  echo \
feline\Cat::says(), "<br />\n";
  echo \
canine\Dog::says(), "<br />\n";
  echo \
animate\Animal::breathes(), "<br />\n"?>

Note that
felineCat::says()
should be
\feline\Cat::says()
(and similar for the others)
but this comment form deletes the backslash (why???)

The 'use' keyword also applies to closure constructs:

<?php function getTotal($products_costs, $tax)
    {
       
$total = 0.00;
       
       
$callback =
            function (
$pricePerItem) use ($tax, &$total)
            {
               
               
$total += $pricePerItem * ($tax + 1.0);
            };
       
       
array_walk($products_costs, $callback);
        return
round($total, 2);
    }
?>
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-2
php at lanar dot com dot au
5 months ago
Be warned that it is not trivial to convert a project to use namespaces. If you add the same namespace to the top of all your files, your application will break.
All objects in the global namespace, such as ArrayObject, must have a backslash (\) prepend to them.
If you use get_class() and instanceof, you will have to make adjustments here to.
If you have an autoloader, you will need to change its behavior.
It can be done, but subtle errors can creep in and are tedious to rectify.
up
-24
guido at go-mobile dot be
1 year ago
Strange, it worked only when I removed the backslash before feline.
So like this is OK : echo feline\Cat::says()
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