PHP Callback Function

• A callback function is a function which is passed as an argument into another function.
• eg:

<?php
function callbackFunc($item) {
  return strlen($item);
}

$strings = ["john", "denver", "david", "jack"];
$lengths = array_map("callbackFunc", $strings);
print_r($lengths);

/*

output:

Array
(
    [0] => 4
    [1] => 6
    [2] => 5
    [3] => 4
)

*/
?>

PHP & JSON

• PHP has some built in functions to handle JSON.
• json_encode: used to encode value to json format

<?php
    $user = array("Name"=>"John DOe", "Age"=>37);
    echo json_encode($user);
?>

• json_decode: used to decode json to php associative array

<?php
    $json = '{"Name":"John Doe","Age":37}';
    var_dump(json_decode($json));
?>

Exception Handling

• An exception is an object that describes an error or unexpected behaviour of a PHP script.
• throw keyword allow user to throw an exception.

try {
  if (condition) {
    throw new Exception("Error here");
  }
} catch(Exception $e) {
  
} finally {

}

• If any exception occured or thrown then the catch block executes.
• finally block will always run.

Others

• Apart from this I have added exception handling in Github Timeline assignment
• Also did UI changes and Email templates.``