[SOLVED] If statement returning true when they shouldn't.

[pocobueno1388]

I have a variable named "statement". This variable holds what would go in an IF statement, like so:

 

if ($statement)

 

Here are some possible values of $statement:

12 >= 15
13.2 >= 13.1
12.1 >= 10.3
18 >= 16.2

 

The problem is, no matter what $statement holds, the IF statement ALWAYS comes back true, even if it isn't. I even echo out the value of statement and it looks just fine, so I'm not sure why it isn't working properly.

 

Here is the code:

<?php

//Make sure the IF statement looks okay (error check)
echo "if ($statement)<br>";
    
    //Process the IF statement.
    if ($statement) echo 'TRUE<p>'; else echo 'FALSE<p>';
?>

 

Here is the output for the above code, this code is in a foreach loop, so thats why there are multiple lines.

if (12 >= 15)
TRUE

if (12 >= 15)
TRUE

if (12 >= 15.3)
TRUE

if (12 >= 15)
TRUE

if (12 >= 15.3)
TRUE

 

As you can see, it is coming out true even if it shouldn't.

 

Any help would be greatly appreciated =D Thanks.

 

 

[per1os]

http://www.phpfreaks.com/forums/index.php/topic,145271.html

 

I would suggest reading that.

[pocobueno1388]

Thank you Frost, but I'm still a bit confused. I saw the functions you posted:

 

<?php

function condition_run($condition_str) {
      $and_portion = explode("&&", $condition_str);
      
      if (count($and_portion > 0)) {
             $condition_true = true;
             foreach ($and_portion as $and) {
                     $rest = explode(" ", $and);
                     
                      if (!condition_test($rest[0], $rest[2], $rest[1])) {
                             $condition_true = false;
                             break;
                      }
              }

              return $condition_true;
      }

      return false;
}

function condition_test($val1, $val2, $condition) {
     switch ($condition) {
            case '<':
                   if ($val1 < $val2) {
                          return true;
                   }
            break;

            case '>':
                    if ($val1 > $val2) {
                          return true;
                   }
            break;
     }

     return false;
}

?>

 

But I'm not really sure how to make this fit my code.

 

Here are the variables in my code:

<?php

$f[$stat]; //This holds just a single number
$condition; // This holds the condition AND a number together.
               //An example of what it could look like is this: >= 5
?>

 

I know I could use explode() on the $condition and separate the condition from the number...but I still wouldn't know how those functions could help me, as the condition_test() function doesn't check for conditions like ">=" or "<=".

 

In the first function, I see that it assumes your working with "&&" as the condition...which is not what I want.

 

Is there some sort of built in PHP function that compares numbers? I had no idea that it wouldn't be valid with an if statement. I tried the IF statements above in a different file, and the ones that should have returned false actually did return false, so are we sure that is the problem?

[per1os]

It is simply an example, if you do not want to do complex conditions you modify the code, so you do not split at &&.

 

<?php

function condition_run($condition_str) {
       $condition_true = true;
       $rest = explode(" ", $condition_str);
        if (condition_test($rest[0], $rest[2], $rest[1])) {
                return true;
        }

         return false;
}

function condition_test($val1, $val2, $condition) {
     switch ($condition) {
            case '<':
                   if ($val1 < $val2) {
                          return true;
                   }
            break;

            case '>':
                    if ($val1 > $val2) {
                          return true;
                   }
            break;
            // add as many cases as you want.
            case '>=':
                    if ($val1 >= $val2) { return true;}
            break;
     }

     return false;
}

?>

 

The basic gist of it is, take that code and manipulate it to suit your needs. It is just like a template.

 

 

EDIT::

As I explained in the other post, $string = "1 > 2";  will return true as a string returned as an int > 0 which php generally takes any number in an if greater than zero as being true IE:

 

<?php
if ('this is just a simple string') {
   echo 'Wow this is true!';
}

if ('12 < 3') {
    echo 'Wow this is also true!';
}
?>

 

Since it is taking those literally like they are strings, it does not know the difference. You might be able to use www.php.net/eval , but that could be pretty dangerous.

 

IE:

 

<?php
if (eval("<?php if ($statement) { return true;}else {return false;} ?>")) {
    echo 'Returned true!';
}else {
    echo 'Returned False!';
}
?>

 

Unsure if it will work but yea.

[pocobueno1388]

Wooooo, I got the condition_test() function to work and do what I wanted with the script. Thank you very much Frost xD