Is there a way to convert a string to a numeric string ?

[jd2007]

Is there a way to convert a string to a numeric string ?

[Guest]

You can try casting. I'm not entirely sure what you mean though:

 

<?php

    $int = 23;
    $string = (string)$int;

// OR

    $string = "$int";

?>

 

Whichever you prefer

[jd2007]

i want this string '9-1' to give me the answer 8.

[AndyB]

eval()

[jd2007]

i get this :

 

Parse error: syntax error, unexpected T_LNUMBER in C:\AppServ\www\Calculator\calc.php(34) : eval()'d code on line 1

 

my code:

 

<?php

class Calculator
{
private $localhost;
    private $username;
private $password;
private $db;

function connectdb($l, $u, $p, $d)
{
     $this->localhost=$l;
 $this->username=$u;
     $this->password=$p;
     $this->db=$d;
     mysql_connect($this->localhost, $this->username, $this->password);
 mysql_select_db($this->db);
}

function checkvalue($value)
{
     $this->que="select math from calcs where cal='$value'";
$this->result=mysql_query($this->que);
     $this->row=mysql_fetch_row($this->result);
 if ($this->row[0]=="add")
	{
	 echo "+";
	}
 echo $this->row[0];
}

function result($exp)
{
     echo eval($exp);
}

}
//echo (3+(3/4))-(5/6)+(1+(1/3));
$cal=new Calculator;
$cal->connectdb("localhost", "root", "*****", "calculator");
$cal->checkvalue($_GET["n"]);
if ($_GET["n2"]=="")
{

}
else
{
$cal->result($_GET["n2"]);
}
?>

[Guest]

I may be wrong, but I believe eval() can't be used with variables (it has to be raw string data).

 

EDIT: You can, nevermind. However, you have to put valid PHP inside that eval...

 

You will need that trailing semicolon at the end of the statement inside eval(), and simply putting in the expression into eval will get you nothing. You need to add an echo or something

 

<?php
   $str = '1+2';
   $s = '$x = '.$str.';';

   eval($s);
?>

 

Theoretically, that should work. But hey, 9:30am and PHP don't mix XD