我正在从O'reilly媒体书籍“ProgramingPHP”学习PHP，我偶然发现了这个:functionadd_up($running_total,$current_value){$running_total+=$current_value*$current_value;return$running_total;}$numbers=array(2,3,5,7);$total=array_reduce($numbers,'add_up');echo$total;array_reduce()行调用了这些函数:add_up(2,3)add_up(11,5)add_up(36,7)//$t