检查是否存在类常量

Question

How can I check if a constant is defined in a PHP class?

class Foo {
    const BAR = 1;
}

Is there something like property_exists() or method_exists() for class constants? Or can I just use defined("Foo::BAR")?

Answer 1

Yes, just use the class name in front of the constant name.

http://www.php.net/manual/en/function.defined.php#106287