How pass data between methods PHP. Code examples

function method1($data){
  // Do something with $data
  method2($data);
}

function method2($data){
  // Do something with $data
}

$data = 'Hello World!';

function method1(){
  global $data;
  // Do something with $data
  method2();
}

function method2(){
  global $data;
  // Do something with $data
}

function method1(){
  $data = 'Hello World!';
  return $data;
}

function method2(){
  $data = method1();
  // Do something with $data
}

In WP:

function method1($data){
  // Do something with $data
  do_action('my_custom_hook', $data);
}

function method2($data){
  // Do something with $data
}
add_action('my_custom_hook', 'method2');