what is error in this eval code?

Question

 eval('class this {  ');

 eval('function this($l1,$l2) {
  if($l1==0) { throw new ErrorException("error"); }
  echo $l1.$l2;
  }}');

try {
 $t = new this(0,1);
}
catch(Exception $e) {
 echo $e->getMessage();
}

Why is this code not working?

Errors:

Parse error: syntax error, unexpected $end, expecting T_FUNCTION in .......(4) : eval()'d code on line 1

Parse error: syntax error, unexpected '}' in.......(9) : eval()'d code on line 4

Fatal error: Class 'this' not found in .......on line 12

Answer 1

You can't eval() an unclosed statement like class this {. You'd have to put the entire block into one string and run the eval() once.

That said, there is probably no reason to use eval() in the first place. What are you trying to do?

Answer 2

eval accepts complete and valid piece of php code. class this { is not valid, bacause there is no } in the end.

Answer 3

Like Pekka said, though you could append the code to eval() in a variable like so:

$textToEval = 'class this {  ';
$textToEval .= 'function this($l1,$l2) {
     if($l1==0) { throw new ErrorException("error"); }
     echo $l1.$l2;
     }}';
eval($textToEval);