使用method_exists
,它检查所有方法,包括父类。
示例:
class Toot {
function Good() {}
}
class Tootsie extends Toot {
function Bad() {}
}
function testMethodExists() {
// true
var_dump(method_exists('Toot', 'Good'));
// false
var_dump(method_exists('Toot', 'Bad'));
// true
var_dump(method_exists('Tootsie', 'Good'));
// true
var_dump(method_exists('Tootsie', 'Bad'));
}
如何检查该方法是否只存在于当前类而不存在于父类(即Tootsie
)?
由于v.4.0.5 php有get_parent_class()方法,该方法返回父类。所以你可以处理它而不需要重新思考:
class A
{
function a() { /* ... */}
function b() { /* ... */}
}
class B extends A
{
function b() { /* ... */}
function c() { /* ... */}
}
function own_method($class_name, $method_name)
{
if (method_exists($class_name, $method_name))
{
$parent_class = get_parent_class($class_name);
if ($parent_class !== false) return !method_exists($parent_class, $method_name);
return true;
}
else return false;
}
var_dump(own_method('B', 'a')); // false
var_dump(own_method('B', 'b')); // false
var_dump(own_method('B', 'c')); // true
如果你需要知道该方法是否存在于给定的子类中,而不管父类中是否存在,你可以这样做:
$reflectionClass = new ReflectionClass($class_name);
if ($reflectionClass->getMethod($method_name)->class == $class_name) {
// do something
}
您可以使用反射
$refl = new ReflectionClass($class_name);
if($refl->hasMethod($method_name)){
//do your stuff here
}
有关更多信息,ReflectionClass
基于上面的@失眠答案,但在该方法根本不存在的情况下工作:
function methodImplementedInClass($className, $methodName) {
// If this class doesn't have the method at all, return false
if (!method_exists($className, $methodName)) {
return false;
}
// Now check if the method was implemented in this class or in some parent
return (new ReflectionClass($className))->getMethod($methodName)->class == $className;
}
对我来说,问题是检查扩展类中是否存在方法,而不是父类中的父类
以Elantcev Mikhail的上述例子为例,它看起来更像这样:-
class A
{
function a() { /* ... */}
function b() { /* ... */}
public function own_method( $method_name )
{
if (method_exists($this, $method_name))
{
return true;
}
else return false;
}
}
class B extends A
{
function b() { /* ... */}
function c() { /* ... */}
}
$b = new B;
var_dump($b->own_method('c')); // true
你为什么要这么做?
我有一个类BaseModel,我在其中格式化扩展模型中属性的提示:
class BaseModel
{
public function attributeHelp($attributeName)
{
if (method_exists($this, 'hints') && array_key_exists($attributeName, $this->hints()))
{
return '<i html for nicely formatted hint'
. $this->hints()[$attributeName]
. '"></i>';
}
return false;
}
}
然后在我的数据模型中
class Customer extends BaseModel
{
public function hints()
{
return [
'customer_name' => 'please use your fullname ...',
'some other attribute' => 'some other description'
];
}
}
这是我的解决方案,使用反射并检查反射方法中涉及的实际类。
<?php
class Base {
public function BaseOnly() {
}
public function Extended() {
}
}
class Child extends Base {
public function ChildOnly() {
}
public function Extended() {
}
}
function childMethodExists($baseClass, $childClass, $methodName) {
if (!method_exists($childClass, $methodName)) {
return false; // doesn't exist in the child class or base class
}
if (!method_exists($baseClass, $methodName)) {
return true; // only exists on child class, as otherwise it would have returned above
}
// now to check if it is overloaded
$baseMethod = new ReflectionMethod($baseClass, $methodName);
$childMethod = new ReflectionMethod($childClass, $methodName);
return $childMethod->class !== $baseMethod->class;
}
var_dump(childMethodExists(Base::class, Child::class, 'BaseOnly')); // false
var_dump(childMethodExists(Base::class, Child::class, 'ChildOnly')); // true
var_dump(childMethodExists(Base::class, Child::class, 'Neither')); // false
var_dump(childMethodExists(Base::class, Child::class, 'Extended')); // true