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如果把变量作为常量的名称?

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2016-06-06 20:47:341384browse

define('DBNAME','test');
$val = 'DBNAME';
echo eval($val);

回复内容：

define('DBNAME','test');
$val = 'DBNAME';
echo eval($val);

火速解答

eval是安全性最差的实践，几乎没有之一。请永远不要使用eval。

使用字符串作为名称请求常量的值，请直接用constant函数。

define("MAXSIZE", 100);
echo MAXSIZE;
echo constant("MAXSIZE"); // same thing as the previous line
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