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@NogDogDec 11.2010 — #From the manual:
Also, a quote attributed to the creator of PHP:
?@NogDogDec 11.2010 — #Could you do something like:
eval() and logical operators
I’m trying to evaluate an expression like this:
[code=php]
<?php
$logic = “&&”;
$expr = true;
$variable = eval(“$expr $logic true;”);
var_dump($variable);
// NULL
$logic = “==”;
$expr = true;
$variable = eval(“$expr $logic true;”);
var_dump($variable);
// NULL
?>
But it’s completely eating it. I also tried “&&” instead of “==”.
I would like it to work like this:
[code=php]
$logic = “&&”;
$expr = true;
$variable = eval(“$expr $logic true;”);
var_dump($variable);
//bool(true)
If it’s any help:
[code=php]
$logic = “&&”;
$expr = true; //pubic boolean
$variable =<<<EOS
$expr $logic true;
EOS;
$result = eval($variable);
var_dump($variable);
echo “n”;
var_dump($result);
/* $variable */
//string(10) “1 && true;”
/* $result */
//NULL
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@NogDogDec 11.2010 — #From the manual:[B]eval()[/B] returns NULL unless return is called in the evaluated code, in which case the value passed to return is returned.[/quote]
Also, a quote attributed to the creator of PHP:
If eval() is the answer, you're probably asking the wrong question.[/quote]
?
0
@NogDogDec 11.2010 — #Could you do something like:[code=php]
function compare($expr1, $operator, $expr2)
{
switch(strtolower($operator)) {
case '==':
return $expr1 == $expr2;
case '>=':
return $expr1 >= $expr2;
case '<=':
return $expr1 <= $expr2;
case '!=':
return $expr1 != $expr2;
case '&&':
case 'and':
return $expr1 && $expr2;
case '||':
case 'or':
return $expr1 || $expr2;
default:
throw new Exception("Invalid operator '$operator'");
}
}
[/code]