How can I print hello in Drupal?


create a module
  .info file
  .module file
Create a path to respond to
  use a menu hook to do this
  menu hook will have a php call back
Create a php function
  write the callback function
  return an html string
See the result
  The string will showup in the content area of the page

This idea can be extended to use render arrays.

You can see an example of this here


create a module
  .info file
  .module file
Create a path to respond to
  use a menu hook to do this
  menu hook will have a php call back
Create a php function
  write the callback function

  return a php data array
  identify in the data array the render function
Register the render function
  in the module theme hook register the render function
write the render function
  write the render function
  retrieve the data to render
  return html string 

See the result
  The string will showup in the content area of the page

here is an example of this