找出静态类中是否存在方法 [英] Find out if a method exists in a static class

问题描述

我要检查的是我正在创建的库中是否存在函数，该函数是静态的.我已经看过function和method_exists，但是还没有找到一种允许我在相对上下文中调用它们的方法.这是一个更好的示例:

I want to check is a function exists in a library that I am creating, which is static. I've seen function and method_exists, but haven't found a way that allows me to call them in a relative context. Here is a better example:

class myClass{
    function test1()
    {
        if(method_exists("myClass", "test1"))
        {
            echo "Hi";
        }
    }
    function test2()
    {
        if(method_exists($this, "test2"))
        {
            echo "Hi";
        }
    }
    function test3()
    {
        if(method_exists(self, "test3"))
        {
            echo "Hi";
        }
    }
}
// Echos Hi
myClass::test1();
// Trys to use 'self' as a string instead of a constant
myClass::test3();
// Echos Hi
$obj = new myClass;
$obj->test2();

如果函数存在，我需要能够使test 3 echo Hi，而无需将其移出静态上下文.假设用于访问该类的关键字应该是"self"，因为$ this是用于分配的类.

I need to be able to make test 3 echo Hi if the function exists, without needing to take it out of static context. Given the keyword for accessing the class should be 'self', as $this is for assigned classes.

推荐答案

static::class自PHP 5.5起可用，并将返回"

static::class is available since PHP 5.5, and will return the "Late Static Binding" class name:

class myClass {
    public static function test()
    {
        echo static::class.'::test()';
    }
}

class subClass extends myClass {}

subClass::test() // should print "subClass::test()"

get_called_class() 相同，并在PHP 5.3中引入

get_called_class() does the same, and was introduced in PHP 5.3

class myClass {
    public static function test()
    {
        echo get_called_class().'::test()';
    }
}

class subClass extends myClass {}

subClass::test() // should print "subClass::test()"

---

get_class() 函数如果在类中调用php 5.0.0，则不需要任何参数，它将返回声明该函数的类的名称(例如，父类):

---

The get_class() function, which as of php 5.0.0 does not require any parameters if called within a class will return the name of the class in which the function was declared (e.g., the parent class):

class myClass {
    public static function test()
    {
        echo get_class().'::test()';
    }
}

class subClass extends myClass {}

subClass::test() // prints "myClass::test()"

__CLASS__魔术常数的作用相同[链接].

class myClass {
    public static function test()
    {
        echo __CLASS__.'::test()';
    }
}

class subClass extends myClass {}

subClass::test() // prints "myClass::test()"

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