[blockquote]在trait继承中，优先顺序依次是：来自当前类的成员覆盖了 trait 的方法，而 trait 则覆盖了被继承的方法[/blockquote]

class A {
    public function sayHello() {
        echo "A";
    }
}
trait B {
    public function sayHello() {
        parent::sayHello();
        echo "B";
    }
}
class C extends A {
    use B;
}
$c = new C();
$c->sayHello();    

上述打印结果是：AB 

class A {
    public function sayHello() {
        echo "A";
    }
}
trait B {
    public function sayHello() {
        parent::sayHello();
        echo "B";
    }
}
class C extends A {
    use B;
    public function sayHello() {
        echo "C";
    }
}
$c = new C();
$c->sayHello();

上述打印结果为：C