PHP - Eval()无法正常工作[关闭]

My code isn't working, what am i doing wrong?

Its a very simple and small script

<textarea name="codebtn" id="code"></textarea> 
<input name="code" type="submit" /> 
</form> 
<br> 

Result 
<br> 
<?php 


if(isset($_POST["code"])) { 

$lol = $_POST["codebtn"];

eval('?>' . $lol .'<?php'); 

} 

?>

This has nothing to do with eval, and everything to do with your form.

Because <input name="code" /> has no value attribute, it is not being sent as part of the request, thereby causing isset($_POST["code"]) to fail.

Try:

<input type="submit" name="code" value="lol" />

As an aside, what's wrong with echo $lol instead of eval?

You're not defining the beginning of form:

<form action="" method="post">
<textarea name="codebtn" id="code"></textarea> 
<input name="code" type="submit" /> 
</form>