php - 整数结果中的字符串表达式

Question

经过大量的操作，我得到了一些像:

$exr = "2+3/1.5";

我怎样才能得到这个表达式的结果？像这样:

$result = (floatval)$exr; // show: 4

当然不行。我只有 2 个，第一个符号。有什么简单的方法可以解决这个问题吗？

Answer 1

您可以使用 PHP eval像这样的功能:

$exr = '2+3/1.5';
eval('$result = ' . $exr . ';');
var_dump($result);
// float(4)

仔细阅读此说明:

Caution: The eval() language construct is very dangerous because it allows execution of arbitrary PHP code. Its use thus is discouraged. If you have carefully verified that there is no other option than to use this construct, pay special attention not to pass any user provided data into it without properly validating it beforehand.