doushi6947 2015-10-29 17:09
浏览 62
已采纳

php将字符串转换为条件语句

I have a bi dimensional array of array with homogeneous values.

$input = array(
     'x' => 100, 'y' => 101, 'type' => 'yes', value => 10
), array(
     'x' => 110, 'y' => 101, 'type' => 'no', value => 10
), array(
     'x' => 120, 'y' => 102, 'type' => 'yes', value => 99
);

I need to find out a way to write a function to filter values passing a "text" filter as input:

//extract all values when $tye = yes and $value is greater than 10
custom_filter($input, "type = yes and value > 10");

//extract all values when $x is equal to $y
custom_filter($input, "x = y");

//filter all values for x is pair and y is odd
custom_filter($input, "x % 2 = 0 and y % 2 > 0");  

function custom_filter($input_array, $condition) {
     (...)
}

Is there a way to "translate" $condition parameter from human readable statement to a php conditional statement?

  • 写回答

1条回答 默认 最新

  • douduan5086 2015-10-29 17:28
    关注

    I think this is the easiest way:

    $input = [
         ['x' => 100, 'y' => 101, 'type' => 'yes', 'value' => 10],
         ['x' => 110, 'y' => 101, 'type' => 'no', 'value' => 10],
         ['x' => 120, 'y' => 102, 'type' => 'yes', 'value' => 99]
    ];
    
    function custom_filter($array, $eval) {
        $validate = function ($item) use($eval) {
            extract($item);
            eval('$valid = ' . $eval . ';');
    
            return $valid;
        };
    
        return array_filter($array, $validate);
    }
    
    //extract all values when $tye = yes and $value is greater than 10
    var_dump(custom_filter($input, '$type == "yes" && $value > 10'));
    
    //extract all values when $x is equal to $y
    var_dump(custom_filter($input, '$x == $y'));
    
    //filter all values for x is pair and y is odd
    var_dump(custom_filter($input, '$x % 2 == 0 && $y % 2 > 0'));
    

    Well, you have to write a php code as a condition for extracted values.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥15 求差集那个函数有问题,有无佬可以解决
  • ¥15 【提问】基于Invest的水源涵养
  • ¥20 微信网友居然可以通过vx号找到我绑的手机号
  • ¥15 寻一个支付宝扫码远程授权登录的软件助手app
  • ¥15 解riccati方程组
  • ¥15 display:none;样式在嵌套结构中的已设置了display样式的元素上不起作用?
  • ¥15 使用rabbitMQ 消息队列作为url源进行多线程爬取时,总有几个url没有处理的问题。
  • ¥15 Ubuntu在安装序列比对软件STAR时出现报错如何解决
  • ¥50 树莓派安卓APK系统签名
  • ¥65 汇编语言除法溢出问题