PHP中的get_defined_funciton和get_defined_vars

<?php 
    $zongzi = "adfasdf";
    //将$zongzi作为数组的key,adfasdf作为数组的值返回
    $val = (get_defined_vars());    
    echo $val['zongzi'];
    
    
    function zongzi(){
        echo "adfads";
    }
    
    $function = get_defined_functions();
    //将自定义的函数获取,函数名作为数组的key,函数返回的结果作为值,再扔给了user
    var_dump($function['user']);    
    echo $function['user']['zongzi'];
?>