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关于运算符的有关问题。为毛这样

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Release: 2016-06-13 13:16:41
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关于运算符的问题。为毛这样?

PHP code
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if($item[$column_name] .$operation. $info)
        {
            echo $item[$column_name] .$operation. $info;echo '=====true';echo '<br>';
            return true;
        }else{
            echo $item[$column_name] .$operation. $info;echo '=====false';echo '<br>';
            return false;
        }
输出:
508205462=505765854=====true
10>1234567=====true
201234567)返回假,用程序运算出来全部为真??

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------解决方案--------------------
因为有“.”,所以你那些变量当做字符串连接起来了
如果想让他们当做表达式运算,需用 eval 函数

eval('return '. $item[$column_name] .$operation. $info. ';')
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