php - Why can't this be calculated and the result always returns 0?

Question

                    <?php
                    $a = $this->item_info['jhl'];
                    $c = intval($a);
                    $b = $this->item_info['price'];
                    $d = intval($b);

                    echo intval((500 / $c) * $d)
                    ; ?>

$this->item_info['jhl']跟$this->item_info['price'];在数据库里面都是数字，如123，456，789这样的数字

为什么计算结果都是0呢

The database field is varchar

Answer 1

intval(500/intval("789")) = 0
intval(500/intval("345")) = 1,
Same as above

Answer 2

When you encounter this kind of problem, print out each variable. The result of using var_dump（），我猜测是因为$c比500大，然后intval（）对于浮点数只会取整，比如intval（0.5） is 0