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User Contributed Notes 4 notes

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247
Anonymous
12 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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29
Anonymous
7 years ago
Tested on PHP 7.0.5, Windows
The line "use animate;" equals the line "use animate as animate;"
but the "use other\animate;" equals "use other\animate as animate;"

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 other\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
other\animate; //use other\animate as animate;
echo feline\Cat::says(), "<br />\n";
echo
canine\Dog::says(), "<br />\n";
echo
\animate\Animal::breathes(), "<br />\n"; ?>
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11
davidkennedy85 at gmail dot com
8 years ago
In addition to using namespaces and closures, the use keyword has another new meaning as of PHP 5.4 - using traits:

<?php
trait Hello {
public function
sayHello() {
echo
'Hello ';
}
}

trait
World {
public function
sayWorld() {
echo
'World';
}
}

class
MyHelloWorld {
use
Hello, World;
public function
sayExclamationMark() {
echo
'!';
}
}

$o = new MyHelloWorld();
$o->sayHello();
$o->sayWorld();
$o->sayExclamationMark();
?>

More info here: http://php.net/manual/en/language.oop5.traits.php
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8
varuninorbit at yahoo dot co dot in
8 years ago
here is a simple example to use namespace

<?php

namespace app\a{
class
one{
public static function
_1(){
echo
'a one _1<br>';
}
}
}

namespace
app\b{
class
one{
public static function
_2(){
echo
'b one _2<br>';
}
}
}

namespace
app{

echo
a\one::_1();
echo
b\one::_2();
echo
a\two::_1();
}

namespace
app\a{
class
two{
public static function
_1(){
echo
'a two _1<br>';
}
}
}

prints
a one _1
b one _2
a two _1
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