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    User Contributed Notes 4 notes

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    247
    Anonymous
    13 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);
    }
    ?>
    up
    29
    Anonymous
    8 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"; ?>
    up
    11
    davidkennedy85 at gmail dot com
    9 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
    up
    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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