How to avoid Notices and warnings errors in PHP code.

While writing PHP code, we often get errors like warnings and notices.

To avoid them, following are some best practises:

1) Always check if a variable is set before using it.

For example:

$age = $_GET['age'];

Should be replaced by

$age = isset($_GET['age']) ? ($_GET['age'] : '';

Reference:

http://php.net/manual/en/function.isset.php

2) Always check if array is not empty before looping over it.

For example:

foreach ($arr as $elem) {
  // Your code.
}

Should be replaced by:

if (! empty($arr)) {
 foreach ($arr as $elem) {
   // Your code.
 }
}

Reference:

http://php.net/manual/en/function.empty.php