[SOLVED] "Catchable fatal error: Object of class input could not be converted to string"

Skyer · 03-12-2012, 03:14 AM

Hello,
I'm experiencing following error in my php code:

Code:

Catchable fatal error: Object of class input could not be converted to string in /home/skyer/.../class/input.php on line 16

The source code looks like this: (line 16 is the one with preg_match()

Code:

class input
{
private $id="/^[0-9]{1,4}$/";

	public function Check_input($type,$input)
	{
		
		if (!isset($this->$type)) {if (DEBUG) echo 'input::Check_input():Cond1:variable doesn\'t exist'; return 0;}
		if (preg_match($this->$type,$input)==0) {if (DEBUG) echo "input::Check_input($this->$type,$input):Cond2:input not of expected character";return 0;}
		
	}
}

It seems to me that the problem is that PHP can't convert $this->$type into string, but I don't know why. $this->$type should be $this->id, and that's defined right above the function.

If I use $this->id directly instead of $this->$type, code works as expected.

Thank you for your help,

Skyer

Skyer · 03-12-2012, 04:13 AM

Alright this is funny,
I took out the $this->$type from the string and concatenated with the rest, and it seems to work now:

Code:

if (preg_match($this->$type,$input)==0) {if (DEBUG) echo "input::Check_input(".$this->$type.",$input):Cond2:input not of expected character";return 0;}

Problem solved - sort of, but I'd still like to hear some explanation of this.

Skyer

ntubski · 03-12-2012, 11:04 PM

It's because you used the simple syntax for string interpolation, but it doesn't handle complex expression like $object->$property.