trait 可以组合多个特性到一个类中，有点像汽车装配厂

<?php

trait BaseEat
{
    public function eat()
    {
        echo 'eat' . PHP_EOL;
    }
}

trait BaseSleep
{
    public function sleep()
    {
        echo 'sleep' . PHP_EOL;
    }
}


class Person
{
    use BaseEat, BaseSleep;

}


$person = new Person();

$person->eat();
$person->sleep();
// eat
// sleep

参考
PHP之Trait详解