PHP Tips - using error_reporting to help you |Tech Lull

In PHP 5, the default level is E_ALL & ~E_NOTICE. While it is nice to hide the 'Notice' messages, it is better to set the error reporting level to just E_ALL. Notice messages usually tell you best practice things like if a variable has not been initiated. If messages are hard to get rid of, this can indicate underlying issues with program logic. For example:


$GLOBALS["foo"]["path"]["relative"]["bar"]["images"] = 'something';
...
Notice:  Undefined index:  foo

The question of 'why use a 5 dimensional array?' comes up. (this is just an example)

As developers we should strive to have high quality code and use all the tools we are provided with - one of them being error reporting.

for more on error_reporting function


//instead of 
error_reporting(E_ALL & ~E_NOTICE);

//use
error_reporting(E_ALL);

the most common reason for E_NOTICE messages are not initiating a variable or not ensuring that a variable is set before trying to check it's value.

1) initiate all variables


function a(){
  if($b){
    $html .= 'something';
  }else{
    $html .= 'something else';
  }
  return $html;
}

will produce the message


Notice: Undefined variable: html ...

function a(){   
  $html = '';   
  if($b){
    $html .= 'something';
  }else{
    $html .= 'something else';
  }
  return $html;
}

is better. this is a practice to get into, for security and other reasons

2) if you get errors on a class variable


if($this->some_attribute){;}

being not defined, then you should define it!


class foobar{
 private $some_attribute;
}

For $_GET, $_POST, $_SESSION, $_COOKIE, check the variable is set before trying to use it's value


if($_GET['id'])

should be


if(isset($_GET['id'] && $_GET['id'])

3) use quotes on word array indices. PHP is usually smart enough to guess, but do not make it. example:


 //bad
echo $animal[dog];

//good
echo $animal['dog'];

back to PHP tips...

Similar entries

using error_reporting to help you