检查同一个类中是否存在多个方法？

Is there a way to verify if multiple methods exists in same class?

class A{
    function method_a(){}
    function method_b(){}
}

if ( (int)method_exists(new A(), 'a', 'b') ){
    echo "Method a & b exist";
}

I'd probably have used interface here:

interface Foo {
  function a();
  function b();
}

... then, in the client code:

if (A instanceof Foo) {
   // it just has to have both a() and b() implemented
}

I think this more clearly shows your real intent then just checking for methods' existence.

You need to check each method individually:

$a = new A();

if(method_exists($a, 'method_a'))...
if(method_exists($a, 'method_b'))...

You can't check more than one method in one function call

Don't think that such functionlity exists, but you can try get_class_methods and compare arrays of class methods and your methods, e.g:

$tested_methods = array('a', 'b', 'c');
if (sizeof($tested_methods) == sizeof(array_intersect($tested_methods, get_class_methods("class_name"))))
    echo 'Methods', implode(', ', $tested_methods), ' exist in class';

use get_class_methods:

class A {
  function foo() {
  }
  function bar() {
  }
}

if (in_array("foo", get_class_methods("A")))
  echo "foo in A, ";
if (in_array("bar", get_class_methods("A")))
  echo "bar in A, ";
if (in_array("baz", get_class_methods("A")))
  echo "baz in A, ";

// output: "foo in a, bar in a, "

You can fiddle here: http://codepad.org/ofEx4FER