# class_uses

(PHP 5 >= 5.4.0, PHP 7)

class_uses — Return the traits used by the given class

### 说明

class_uses ( mixed `$class` [, bool `$autoload` = `TRUE` ] ) : array

This function returns an array with the names of the traits that the given `class` uses. This does however not include any traits used by a parent class.

### 参数

`class`

  An object (class instance) or a string (class name).

`autoload`

  Whether to allow this function to load the class automatically through the __autoload() magic method.

### 返回值

An array on success, or `FALSE` on error.

### 范例

Example #1 class_uses() example

    <?php

    trait foo { }
    class bar {
      use foo;
    }

    print_r(class_uses(new bar));

    print_r(class_uses('bar'));

    function __autoload($class_name) {
       require_once $class_name . '.php';
    }

    // use __autoload to load the 'not_loaded' class
    print_r(class_uses('not_loaded', true));

    ?>

以上例程的输出类似于：

    Array
    (
        [foo] => foo
    )

    Array
    (
        [foo] => foo
    )

    Array
    (
        [trait_of_not_loaded] => trait_of_not_loaded
    )

### 参见

- class_parents() - 返回指定类的父类。
- get_declared_traits() - 返回所有已定义的 traits 的数组