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    forward_static_call

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    forward_static_call — 调用静态方法

    说明

    forward_static_call(callable $callback, mixed ...$args): mixed

    使用以下参数，调用通过 callback 参数给出的用户定义的函数或者方法。此函数必须在方法上下文中调用，不能在类外调用。它使用后期静态绑定

    参数

    callback

    要调用的函数或者方法。此参数可以是带类名及方法的 array 或者带函数名的 string。

    args

    要传递给函数的零到多个参数。

    返回值

    返回函数结果，失败时返回 false。

    示例

    示例 #1 forward_static_call() 示例

    <?php

    class A
    {
    const     NAME = 'A';
    public static function     test() {
    $args = func_get_args();
    echo static::    NAME, " ".join(',', $args)." \n";
    }
    }

    class     B extends A
    {
    const     NAME = 'B';

    public static function     test() {
    echo     self::NAME, "\n";
    forward_static_call(array('A', 'test'), 'more', 'args');
    forward_static_call( 'test', 'other', 'args');
    }
    }

    B::test('foo');

    function     test() {
    $args = func_get_args();
    echo     "C ".join(',', $args)." \n";
    }

    ?>

    以上示例会输出：

    B
B more,args 
C other,args

    参见

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    User Contributed Notes 2 notes

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    2
    arthur dot techarts at gmail dot com
    13 years ago
    Example to understand this function and difference with call_user_func:

    <?php
    class Beer {
        const     NAME = 'Beer!';
        public static function     printed(){
            echo     'static Beer:NAME = '. static::NAME . PHP_EOL;
        }
    }

    class     Ale extends Beer {
        const     NAME = 'Ale!';
        public static function     printed(){
                forward_static_call(array('parent','printed'));
                call_user_func(array('parent','printed'));

                forward_static_call(array('Beer','printed'));
                call_user_func(array('Beer','printed'));
        }
    }

    Ale::printed();
    echo     '</pre>';
    ?>
    up
    0
    jhibbard at gmail dot com
    12 years ago
    Example usage via calls outside of the class and within an object:

    <?php
    /**
    * @author Jonathon Hibbard
    */
    class foo {
          # used to verify we're actually setting something..
          private static $value = '';

          /**
       * Simple setter for the static method setValue...
       */
          public static function set($method_identifier, $value_to_pass = '') {
            # make sure we have the right method format...
        # another semi-useful example is like this (useful for REST-like requests...): str_replace(" ", "", ucwords(str_replace("_", " ",  $method_identifier)));
            $static_method = 'set' . ucfirst(strtolower(trim($method_identifier)));

        if(    method_exists(__CLASS__, $static_method)) {
              //Note:  this will not work and will throw PHP Parse error:  syntax error, unexpected '::'
          //__CLASS__::$static_method($value_to_pass);

              foo::$static_method($value_to_pass);

          echo     "\tCalling forward_static_call with pure string and value param:\n";
              forward_static_call(__CLASS__ . "::" . $static_method, $value_to_pass);

          echo     "\tCalling forward_static_call with class, method array and value param:\n";
              forward_static_call(array(__CLASS__, $static_method), $value_to_pass);
        }
      }

          /**
       * Set self::$value to something?
       */
          public static function setValue($value_recieved = '') {
        echo     "\t\tsetValue called with param of " . var_export($value_recieved, true) . "!\n";

        echo     "\t\tSetting Private 'value'...\n";

            self::$value = $value_recieved;

        echo     "\t\tChecking the Private 'value':\n";
        if(!empty(    self::$value)) {
          echo     "\t\t\tPrivate 'value' was set to '" . self::$value . "' as expected!\n";
        } else {
          echo     "\t\t\tPrivate 'value' was not set!\n";
        }

            # Reset...
            self::$value = '';
      }

          /**
       * Create an object and test calling the static method from within this realm...
       */
          public function __construct() {
        echo     "\tCalling from within constructor..\n";
            foo::set('value','Something else from within the instance!');
      }
    }

    echo     "\n============ Calling by static method first ============\n";
    foo::set('value','Something from outside of the foo class!');

    echo     "\n============ Calling by static method without a value next ============\n";
    foo::set('value');

    echo     "\n============ Calling by createing an instance next ============\n";
    new     foo();
    ?>
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