php - 将字符串转换为数学方程

Question

这个问题已经有答案了:

How to make a calculator in PHP? (3 个回答)

How to mathematically evaluate a string like "2-1" to produce "1"? (9 个回答)

已关闭 9 年前。

我只是想将包含方程的字符串转换为实际的 PHP 数学方程，使用 PHP5+ 可以吗？如果是这样，怎么办？

以下是该字符串的一些示例:

$string = "37-0";
$string = "315+10";
$string = "25+50";
$string = "88-13";

如果可能的话，我只是想将它们解析为正确的数学答案

Answer 1

试试这个:

$str = '37 - 0';
eval( '$result = (' . $str. ');' );
echo $result;

检查eval function

Evaluates the given code as PHP.

附注:

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.